Senku was starting to worry about Kohaku. He'd heard her coughing a few times the past few weeks, and while she was probably the healthiest person he knew, her family was historically susceptible to pneumonia. If she kept coughing, if she didn't go to a doctor for help, he'd take her there himself. No need to suffer through an illness easily eradicated by science.
So when Gen led Kohaku to the lab to talk to him, he was a bit ready for a talk about health.
He was not ready for Gen's insistence that Kohaku was coughing up flowers, nor Kohaku's agreement with him, talking about petals and blossoms. Was this some kind of prank?
Then Kohaku coughed for a full forty-three seconds, chest-deep coughs that sounded incredibly painful, and then she spat out a little tsubaki blossom and some tsubaki petals, just as she and Gen had described.
Kohaku was supporting herself with the table, taking wheezing breaths as Gen soothed her. Senku quickly grabbed her some water as well, which she took gratefully.
So, no. Not a prank. Apparently. But…why?
Gen explained it was probably something called 'hanahaki,' a legend, and that they wanted his help. Kohaku coughed up another flower. And then Gen was backtracking, telling him not to worry about it, practically shoving a dazed Kohaku out the door.
Like Senku wasn't going to figure this out. Like he'd leave a friend like that.
He started by masking up and grabbing some tools, then carefully pulled apart the little flowers on his table. Initial observation showed they were, in fact, tsubaki blossoms, with no structural differences. That wasn't enough for him, though, so he'd look for any chemical differences between them and a normal tsubaki blossom, run tests on the petals, see what he could figure out without poking and prodding Kohaku. After that second flower, she'd looked exhausted, and he wanted to let her rest.
He was at it until the next morning (with some time to sleep himself) and only looked up from the tests when Suika started screaming from the little residential area around the lab. There wasn't much reason to scream near the village, he thought as he grabbed his emergency medkit and started running, so someone had likely had a health problem.
The sharp crack of wood breaking was unexpected—for a second he thought it was a gunshot, until he saw the shattered remains of a door on one of the houses.
Taiju stumbled out the door, looking around until his gaze landed on Senku. "Help!" Taiju cried. "Something—something is wrong!"
Senku noticed that it was Kohaku's house they were standing in front of and his stomach dropped. Gen had implied there was time. Time to find an answer, to cure this, before any unhappy 'legend ending' came to pass.
He peered through the door and saw Kohaku on her bed, surrounded by progressively more blood-soaked blossoms. "I'll be right back!" he shouted to Taiju as he dropped the medkit and raced back to the lab. He needed different equipment. What could he try? Where were the flowers coming from? Where were they rooted? Esophagus? Stomach? Spontaneously forming in the throat somehow? He needed his best diagnostic tools and some acids and bases in case he found something to try to dissolve. He shouted at some of the other scientists there to bring an oxygen pump and mask to Kohaku's house as soon as they could, and then he was running back out the door.
So much running this morning. He was glad he'd kept up with his astronaut training—you never knew when you might need to be shot back into space, after all. Or when one of your best friends was dying and you needed to help. One of those was much less desirable than the other.
The outside of the house was swarming with people when he came running back, villagers and modern-timers alike. Kohaku was well-loved by a lot of people—it wasn't a surprise. But it did make reaching her a bit more difficult. He stopped to catch his breath so he could yell and tell them to move.
One of the villagers saw him and cried out, "Senku's here! Get out of the way!" Which was very effective at giving him a path to the door. The villagers even yanked aside some of the more curious modern-timers that didn't move fast enough.
Inside wasn't much better, chaos-wise. Francois was working at the small stove in the center of the hut, various people fluttering around them. On the bed, Ruri was sitting and trying not to cry, a blood-stained cloth in her hand, while Luna (here on vacation for the summer) was checking Kohaku's pulse and keeping an eye on her breathing. As soon as she saw Senku, she vacated the bed and Senku sat opposite Ruri.
"Her pulse is elevated, blood pressure a bit low, and her breathing is raspy but regular," Luna told him, and he nodded in thanks.
Kohaku looked…small. Small and pale and weak. He hated it. Kohaku was loud and fast and vibrant. Healthy and strong. He forgot, sometimes, that she actually had a pretty delicate frame, that she was more than a full head shorter than him, that she was as human as any of them were.
"Wake up, lioness," he said, needing any kind of response from her that wasn't deathly silence.
"Not…a…" Kohaku mumbled, and Senku relaxed a little. He wasn't sure why she hated the nickname so much, but it was definitely a reliable way to get a reaction.
Immediately Ruri was helping Kohaku sit up, cooing to her and cradling her close, and Senku cleared his throat to get Kohaku's attention. She looked at him with slightly dazed eyes and he worried that whatever was causing the flowers was messing with her blood oxygen levels (he was glad he'd told the scientists to bring oxygen). He explained the (new and improved) stethoscope, then brushed her hair aside to reach her back. He had to figure this out.
And then she was coughing again, even more horrible-sounding than before. Ruri went pale as she held her sister and Senku worried she was going to pass out, but she calmly wiped off Kohaku's face and pointedly ignored the new, beautiful, macabre flowers on the blankets.
And the whole time Senku had listened with the stethoscope and left his hand on Kohaku's back, felt it contract and tighten with each cough, trying to figure out where the flowers were coming from. He could try making medical scanners, but a lot of those depended on an ingestible 'marker' chemical to highlight problem areas. What would he even look for? And how long did he have?
Maybe he'd feel…vines or something under her skin, wrapped around her ribs. He rubbed his hand over her back slowly from slide to side, trying to find anything that didn't feel like normal muscle and bone.
Kokuyo gathered Kohaku into his lap and Senku was by necessity forced to pull back his hand.
Then Kohaku was going limp and Senku couldn't let her go that easily. "Lioness," he called to no response. "Wake up! Lioness!" Her eyelids fluttered and stilled. "Kohaku!"
He grabbed her wrist and held his other wrist in front of her nose. Still breathing. Her heart was still beating. She was just…asleep. Suddenly.
Finally the scientists were there with the pump and both cannula and a more sealed mask. Kohaku wasn't turning colors yet, but she had passed out, so he chose the heavier-duty mask and put it in place.
"Luna," he said, "grab heart rate and oxygen level monitors from the clinic in the village." She nodded and ran out, Taiju and Kinro going with her. "Ryusui," he said next, but the man was nowhere to be seen.
Ruri said, "He, Sai, and Minami are getting in contact with Dr Xeno about sending Why-man back to Japan."
Excellent. That's what he had wanted to ask.
"What do we need to do, Senku?" Kokuyo asked.
Senku looked at the older man. There were observations to make and tests to run and symptoms to respond to, but that was in the realm of scientists and medical professionals.
"Father," Ruri said softly, "I think it would be best if we gave them room to work."
Kokuyo blinked rapidly and stood. "Oh, of course, of course." He wavered, though, looking out the doorway and back to his uncharacteristically still daughter. "You…you will call for us if…if anything…"
Senku nodded. Of course he would. Kokuyo was a man of action, though, and doing nothing was not in his nature. "I'll need some kind of broth to feed her in a while," Senku said.
That got Kokuyo a little fired up. "Then we'll make the heartiest broth we can!" He strode out the door, and Senku ignored the little tear that escaped the corner of the older man's eye as he went.
Ruri took a moment longer, brushing Kohaku's hair off her forehead. "I'll be back to help clean her up," she said, then turned to Senku with a serious expression. "I trust you to do your best, Senku." Then she, too, was gone.
Senku would do his best. But this was something he had no experience with, nor precedent for. He'd proceed as he always did, one step at a time with science as his guiding light.
…would it be enough?
He quickly discovered that having Kohaku lay on her back was a terrible idea, since she started coughing up flowers again. To avoid choking her with them, he rolled her on her side. He also kept having to take off the mask to clear out the flowers, and they were starting to coat the inside of the mask in blood. The cannula were less efficient at delivering oxygen than the mask (at least, their stone world versions of them were), but the mask was being compromised by the circumstances, so he made the switch.
Taiju and Kinro came racing through the door, various pieces of machinery in their arms. Luna followed them in, out of breath, but she told them how to set up the machines as she gasped.
As expected, Kohaku's blood oxygen levels were low. As long as they kept monitoring…
The others were starting to leave as well, seeing as there wasn't much to do.
"Gen," Senku called as the mentalist walked past, "stay here for a minute."
"Yes, Senku-chan?" Gen said. His voice was subdued.
"Tell me more about Hanahaki. Everything you know."
Gen sighed. "Senku-chan, it's not…" Senku glared at him and Gen raised his hands. "Alright, alright." He dragged over another chair. "I'll tell you all I can.
"First, it's a disease of unrequited love." He paused and stared at Senku, as if waiting for a reaction. Senku thought he did pretty well at containing his utter bafflement at such stupidity.
Gen smirked a little. "Well, you wanted to know. So yes, Kohaku-chan fell in love with someone, and that person isn't going to love her back—at least, not romantically."
Senku felt his eye twitching but didn't say anything.
Gen went on to describe the various versions of the legend he'd heard, those where the victim died and those where they were cured. The cure was, apparently, hearing that the person the victim loved them back. Or surgery to remove the plants from the victim's lungs that would also take away their ability to feel love or a potion that would do the same.
"That is ten-billion percent bullshit," Senku said after Gen indicated he was finished by leaning backwards.
Gen glanced at Kohaku, and he didn't even need to say the words—Senku understood. Bullshit, maybe, but that didn't change the facts: Kohaku was coughing up flowers and would die without intervention.
"Well, who's the person she likes?" Senku asked. "I didn't know she liked anyone like that at all." He'd continue on with science, but it wouldn't hurt to try the 'traditional' methods. "Tsukasa, maybe…?" he muttered to himself. "Or Hyoga. I've heard they've been getting on well." Both men had partners now, though, so he could understand why she wouldn't want to say anything. "Or Amaryllis? They're good friends…"
Gen sighed. "You're an idiot, you know that?"
"Hey," Senku said with a frown. "I'm being serious here."
Gen shook his head and stood up. "I usually wouldn't say anything at all, but since she's literally dying…Senku, she hasn't been shy about telling people what kind of person she likes best. I know you've heard her say it at least once. You can be smart sometimes—figure it out." Then he left.
Senku sat there, baffled, as he checked Kohaku's blood pressure (low). What on earth did Gen mean by all that?
Had he heard Kohaku say what kind of person she liked? That wasn't the kind of information that he tried to remember, so it took him a few minutes to think of it.
It had been on their first journey to North America, in the wild time they'd reawakened Moz. The man had tried flirting with Kohaku again and been soundly beaten for it. Kohaku was talking to Nikki, who had asked Kohaku what her type was, if not a strong warrior.
"Ha!" Kohaku had said with a smirk. "I'm plenty strong. What do I need another warrior for?" Then she put her hands on her hips and stared out over the water. "No, I don't care about physical strength or looks. I like strength of character. My type is someone who can pursue their dreams endlessly, step by step, until they reach their goal."
Nikki had laughed. "Sounds like you have a crush on Sen~ku~!"
Kohaku had laughed too, and the two of them had gotten back to work. Senku had thought nothing of it, since it had obviously been a joke.
Senku looked at the now pale face of Kohaku. Did she like him? If this legend was to be believed, people got Hanahaki when their love remained unrequited.
And Senku didn't do romance. All his friends knew that. He had so much to do—he didn't have time to waste on nonsense, and a brain in love was the most nonsensical thing he could think of.
But Kohaku didn't wake up. In the two days it took for Ryusui to bring back Why-man, Senku got very little sleep, with the way Kohaku's body seemed to determined to die before it's time setting him on edge—they hadn't had to hook her up to a ventilator yet, but they'd certainly used a fair amount of adrenaline and kept having to monitor her oxygen levels.
Finally, Why-man was there, and they turned Kohaku to stone and revived her.
Immediately her breathing was better, her oxygen levels normal. Senku collapsed onto the chair by her bedside in relief—it had worked.
But she didn't wake up.
And he was confronted with the harrowing realization that he might not be able to save her—that Kohaku would die despite his best efforts.
Luna sent him home at that point. She was adequately trained as a medical professional now, even if she hadn't graduated yet, and promised to call if anything happened.
Taiju had practically carried him out and to his own hut, littered with science paraphernalia and the bare necessities of living. A modern space for a modern scientist.
He couldn't stand it. He left as soon as the coast was clear, running into the woods.
He found himself in the clearing where he'd first met Kohaku. The log that had trapped her was still there, now decomposing a bit. He sat against it, next to the ditch that had saved her life—if it hadn't been there, she would've been squished flat.
Could he even imagine a version of his current success without Kohaku? She had brought him to the village and helped him win them over. Her strength and agility, her sharp eyes and quick mind, had proved to be their saving grace over and over. Any success without Kohaku would have taken years more than it did.
Could he imagine a future success without her? He didn't want to. He loved all his friends dearly, and he was a selfish man—he wanted them all to live and live well.
And these past weeks without Kohaku had been…dull. He'd missed her, he could admit that. He wanted her back.
But did he like Kohaku romantically? Could he?
He had been putting off thoughts of romance, saying it wasn't time, that there was too much to do, but the truth was they were finally at a stable place. People were being woken up the world over, the danger of petrification was gone. Science was advancing, filling in the gaps that the speed-run to the moon had skipped over. Their friends were getting married, starting families.
Now was the time for romance.
Well. Well, then.
So he imagined it, a relationship with Kohaku. A romantic relationship with her.
She was affectionate. She'd want hugs and kisses. And, truth be told, he didn't mind when she touched him, which was maybe telling in itself. Even their fake kiss, so long ago at this point, hadn't disgusted him, only surprised him. That had never happened before. And her tendency to hug him when reuniting—it was nice.
She'd want to spend time with him. She liked helping with his experiments, so that was alright, but as Byakuya had been fond of saying (even to his son that showed no interest in relationships), a romantic relationship needed reciprocity—he'd need to spend time with her, doing things she wanted to do.
That…might be more difficult, but Ukyo and Yuzuriha had been nagging him to relax more, that he was going to work himself to death. There was precedent for that—humans needed time to relax, especially as they got older. And Senku was getting older—little aches and pains had started.
And she'd probably just want to practice fighting or something, and it was fun to watch her fight, so that wouldn't be too bad.
Living together…she was a minimalist by nature, while his space tended to be full of experiments, but they could work something out. Talk. Compromise. They kept similar hours, and while Senku hadn't ever shared a bed with a woman before, he had literally been kicked in the shins for years sleeping next to Chrome—sleeping with another human would be okay.
As far as 'sharing a bed' went…he was open to experimenting. Kohaku was pretty, passionate, and a lot of fun—all things that would make for a good time together. His lack of experience he would make up for with thoroughness and diligence. If she wanted to, that is. He didn't actually know how she felt about sex.
And they could have kids, biological or even adopted, absolutely wild and rambunctious, strong and smart and all stupendous pains in the ass. He smiled as he thought about it. He thought of Kohaku, older, still radiant, teaching those kids how to defend themselves and others. Him, showing them how awesome the world was.
Her smiling at him with affection, her loving him. Him loving her.
He wanted that. It was startling to realize, but he wanted that. He wanted a future with Kohaku. As…as her husband, or whatever.
He grabbed his shirt over his heart. His heart wasn't racing. He wasn't feeling 'twitterpated' or whatever nonsense that was. He just felt like himself, realizing he wanted to spend the rest of his life in a romantic relationship with one of his best friends.
He suppose he did feel warm, thought. Content.
So he stood up, leaving his hand on the old tree for a moment. He wasn't sure which was more unlikely—a disease that made someone cough up flowers, or Ishigami Senku falling in love. He smiled and started walking back to Kohaku's hut. Whatever the case, Kohaku had managed the impossible twice over. They'd find a way to wake her up, and then he could talk to her about starting a future together—and that was pretty exciting.