Senku froze. He hadn't knocked before entering—why would he?—but it seemed Kohaku had thought he would, or would take longer to get ready for bed. To be fair, he usually paced around outside for quite a while before bed, trying to think through his next invention—where he would get the parts, what needed to move and what didn't, ways to lighten weight without sacrificing stability—but he was just plain tired after the heat of the day today and wanted to sleep, so he'd forwent his normal routine and headed to the company bedroom he shared with Kohaku, walking in on the kid changing.

And so made the interesting discovery that Kohaku was not, in fact, biologically male.

Kohaku squeaked and grabbed a blanket to cover up, but Senku had already gotten an eyeful.

There was a beat of silence. Senku walked fully into the room and shut the door behind him. Kohaku looked about ready to burst into tears, so Senku said, "Rest up. Tomorrow will probably be just as hot." And shuffled over to face-plant onto his bed.

Kohaku sniffed. "You…won't make me leave?"

"What for? You're still strong and fast, aren't you?" Senku replied, muffled by the pillow. Damn, these company beds were shit.

"You're not…curious?"

Senku sighed and rolled onto his side to glare at Kohaku, who was sitting on his (her? their?) bed still wrapped in a blanket. "Of course I'm curious. I'm also tired as hell."

Kohaku didn't wilt under Senku's ire. "I'm running away from my father. He wanted to marry me and my sister off to pay his debts."

Senku rubbed the bridge of his nose. "What, you're gonna dump a whole backstory on me now?"

A soft laugh. "No, I guess not. But, um…if you could…"

"What?"

"…not tell anyone," Kohaku finished quietly. "I like working with you. It's the most fun I've ever had."

Senku knew he wasn't the easiest guy to work with. He was demanding and loud and rude (though not as rude as some). He made a face and rolled away again. "Yeah, whatever."

Because it was fun to work with Kohaku, too. Maybe not as easy as working with Chrome, who had wanted to train up to be an engineer himself, but fun.

Then he sighed. "So do I call you as a man or woman or what?"

"Oh! Uh…woman, please."

"How old are you actually?" He'd been thinking fifteen-year-old boy by the voice, and seeing as he was wrong about gender…

"Eighteen."

Sheesh. Way off.

"How old are you?" she asked back. "I never asked."

"Eh? Twenty."

A rustle of fabric, and the lamp dimmed. "Thank you, Senku," Kohaku said in a gentle voice.

"Whatever. Just go to sleep."

Kohaku laughed quietly and then fell silent, and they both drifted off to sleep.

His inventions had been found. He knew it wasn't Kohaku who'd snitched, who'd told those corporate jerks what he'd really been up to in his spare time, but it didn't really matter—he was being taken away, not able to fight back against the strength of the police (actual police, they'd called in actual police officers).

Kohaku was running down from where she'd been checking something on the boiler at this stop, confused and angry. "What are you doing?" she cried. "You can't take our engineer!"

"Another team will take over, kid," someone said gruffly, grabbing her shoulder to keep her back. "Sorry. They might be able to reassign you."

"I don't want a reassignment," she spat, shrugging off the heavy hand easily. "Senku, hang on!"

But he was loaded in the carriage, pulling away, and even Kohaku wasn't fast enough to chase down a police carriage in the city.

She tried, though.

"What a dumb kid," one of the officers said with a laugh. "What's he gonna do, catch up and yell at us?"

Senku glared but held his tongue. Kohaku was many things, but dumb sure wasn't one of them. He willed her to remember what he'd told her about his friends, about the 'safeties' they had—she needed to find Gen, and quickly, not chase Senku himself down.

"Aw, he's crying," another laughed. "And look, he's running off now. Guess he's not all that loyal, huh?"

First they mocked Kohaku for chasing them, then for not chasing them—nice to know the city was being protected by such stellar examples of humanity.

Senku leaned back on his uncomfortable seat and hoped everything they'd put into place would come through. It all depended on Kohaku, though, on her speed and observation to find the right people quickly. There wasn't any more he could do now.

Gen and a guy named Ryusui (they'd met a couple times, briefly) came to get Senku out of jail, which meant Kohaku had been able to find them—good. It was hell just sitting in that boring-ass room.

He'd expected to see her fluffy little mane as soon as he left the building, maybe scowling at him for getting caught, maybe teasing him for needing to be saved, maybe just smiling and happy to see him, but she wasn't on the street. Nor was she at Ryusui's house when they got there.

"So obviously you don't have a job anymore," Ryusui said, lounging on one of his fancy-ass couches "And it was a bit of a hassle to get you out of trouble."

Senku sighed and sat on a more reasonable-looking armchair. "What do you want, you leech?"

"Ha ha, straight to the point! I love it!" Ryusui grinned and leaned forward. "Work for me. I like your ideas, we know or at least knew of each other, and that Kohaku kid said you were smart as hell. From what he said about your work, I'm very interested."

Senku pursed his lips. She hadn't told them who she was, then, but that was fine. She was slow to trust, and Gen and presumably Ryusui enjoyed their lifestyle and behavior, so it was sometimes hard to see the core of them—still bastards, but honorable ones.

More concerning was the complete lack of her in the first place. "Where is Kohaku, anyways?"

Gen frowned. "Odd, he was here when we left to talk to Magistrate Kokuyo."

And something cold settled in Senku's gut. "Magistrate…Kokuyo." That was Kohaku and Ruri's dad, the man in tons of debt, who would sell off his own daughters. "Did you tell Kohaku you were going to see him?" Because Kohaku may have just done something very stupid.

"Of course. Kohaku was the one who told us the man was in debt and could be bought out."

Ryusui snapped. "And for a lot less than I was expecting! Ha ha, even better for me!"

"Yes, I'd heard he was difficult to persuade, but it hardly took any pressure at all for him to accept the bribe," Gen went on, sounding a bit curious.

Kohaku had done something stupid. Senku cursed and scrambled out of his chair, racing for the door.

"Senku?!"

He ignored them and started running, running towards the fancy-ass house in the center of town that Kohaku had described growing up in, trained by governesses and masters, but refusing to break—she was strong and fast, and no one could beat that out of her.

No one but herself.

A motorized carriage pulled up beside him as he ran, startling him, and he saw Gen and Ryusui inside, Ryusui's butler Francois at the wheel. Well, might as well take advantage of the resources. He hopped in, then said, "Take me to the magistrate's house!"

Then he rubbed his face. "That stupid woman," he muttered. She didn't need to sacrifice herself for him.

"Woman?" Gen repeated, intrigued, and Senku scoffed.

"Yeah, didn't you catch on to that, mentalist? Kohaku's well and truly a woman. Guess you're not as good as you say."

"But then what's the problem?" Ryusui said, taking a relaxed sip of brandy (bastard).

"Her dad's the magistrate." Their eyes widened. "And she was running away from him so he wouldn't sell her off to his debtors."

Ryusui knocked on the window. "At haste, Francois!" And the carriage sped up, the noises from outside suggesting they were carving a trail of chaos as they went.

Gen frowned. "So, you think she offered herself up as a bribe instead?"

"I know she did. She's honorable to a fault, and she gave up her own plan for escape so her sister could marry the guy she loved." If she'd helped Chrome and Ruri by offering herself as a steam engine fireman to replace Chrome, it wasn't a stretch to imagine her doing the same kind of thing for him—hadn't she proven over and over how highly she thought of him, how much she wanted him to succeed? He could imagine it—her, showing up and telling her father she'd go along with his plan, if only he let one stupid train engineer who got on the wrong side of some corrupt steam engine business owners out of jail.

The carriage screeched to a stop in front of an ostentatious building and Senku jumped out immediately, running up to the door.

Gen caught his arm before he could start pounding on the door and demanding to be let in. "Now hang on. We can handle this reasonably."

Senku snarled. "That idiot woman is about to ruin her life for me, and I won't allow it!"

Gen chuckled and shook his head. "Interesting. I never thought I'd see the day." Before Senku could ask what the actual hell he meant by that, Gen went on, "Let me do the talking. If you can, sneak away and find Kohaku."

Ryusui came up to them and snapped. "And leave the rest to me!"

Senku took a deep breath and nodded. This would work better as a team.

The butler took forever to answer the door and sneered down at them. "I'm afraid the magistrate isn't at home," he said, eyeing Senku's shabby suit and Gen's somewhat dandy-ish attire. The expression changed when he saw Ryusui—someone rich, well-known, and influential. "Ah, that is…"

Gen was silver-taking his way in, and suddenly they were in the parlor, and Senku slipped out while the butler went to get a maid to bring some food for the guests.

The family rooms would be upstairs, right? So that's where he went, carefully heading up, grateful there didn't seem to be a lot of staff around. Only a few rooms had light coming from under the doors, so he quickly padded over to listen at one door.

"But why did you come back?" said a young woman's voice. "After all that trouble to get you and Ruri out…"

"I'm sorry, Nikki. This…was a bit unplanned."

"Yeah, no shit," Senku couldn't help but mumble, and suddenly the door was open and Kohaku was looking down at him with wide blue eyes. He raised an eyebrow. She was dressed up in an evening gown, her hair forcibly tamed into a delicate updo. Clean and even radiant. "Going to a party? You're all decked out."

She scowled and grabbed his collar, pulling him into the room and closing the door behind him. "What the hell are you doing here?"

"Oh, stopped by for tea," Senku said, straightening his shirt. "I heard they'd got some fancy shit here to try."

"You're impossible," Kohaku growled, throwing up her hands and stomping away.

Senku smiled. Still her, under all that fancy fabric and cleanliness, and that settled him. "Just improbable. Now come on, what's the fastest way out of here?"

She looked confused.

"We can still make the train back to my parent's ranch if we go now, so hurry it up, lioness."

Her face flushed. "I'm not a lioness," she snapped. Then she sagged. "And…I can't. Senku, you have to go."

"Not without you."

Her lip trembled. "Please. I…I've done all I can, so…" She sniffed and then scowled. "So don't mess it up! Get out of here!"

He'd be more afraid of her shouting if he didn't know she was terrified—the way her eyes kept darting to the door gave her away. "I'm not messing anything up," he snapped back, "as long as we go now."

Big, heavy footsteps. Senku's stomach sank like lead. Kohaku's expression changed to open fear. Her companion, Nikki, who'd been quietly observing, ran forward—

—and a large older man came through the door, followed by a young, handsome, dark-haired man.

"Moz," Kohaku growled, then stopped, and lowered her head. "Father." Nikki bowed and stayed there. Senku put his hands on his hips, showing no deference at all and observing their opponents.

Her father had obviously seen better days. Gaunt and pale, not a trace of resemblance—except for that stubborn look. Senku knew it well.

"What is the meaning of this?" The man asked in a rough voice. "I told all the nonessential staff to leave today on threat of termination—get out! And don't come back!"

And Senku realized the man was talking to him and nearly started laughing. Didn't know who he was, then. Interesting. How could he play this?

"Father, he's—"

"I'm here to ask Kohaku to run away with me," he said.

Kohaku spun around. "W-what?!"

Because the younger creep was probably the guy the magistrate was trying to marry Kohaku off to, right? And those kinds of people were weird about their definitions of value—so…what if he made her seem 'worthless?'

"After all those nights together—didn't they mean anything to you?"

Kohaku's entire face flushed red and she squeaked.

As expected, the young man's cocky smirk was falling. The magistrate was looking panicked. Just had to keep it going.

"So I'm here to do right by you."

Another squeak was his answer. Her father was looking apoplectic and the young man was scowling.

Senku pulled out a circle of metal in his pocket—a souvenir from trying to make some tools out of prison bedsprings—and got into the traditional position, one knee, holding out a ring.

Kohaku's brow furrowed as she looked at the 'ring,' her blush fading a little. Probably wondering what the hell he was holding. Her eyes would catch that it wasn't as it seemed.

The men were too far away to see that it was obviously a fake. They were arguing about Kohaku being "untouched" and thus worth less, firmly cementing them as some of the stupidest people Senku had ever met.

"What…?" Kohaku asked, reaching out.

That was enough for him. He stood up and wrapped his arms around her, bending down, pressing his lips to the corner of her mouth. She stiffened.

Before he could tease her about blowing their cover by being too stiff, though, she turned her head a little, and suddenly they were actually kissing, her hands sliding around to his back . It was his turn to stiffen up.

…soft, and warm, and…

…he'd…pull away…any second now…

Then he got punched in the skull and went flying, and the next few seconds got a bit muddled in his head.

When his ears stopped ringing, he pushed himself up on his elbows in time to see Kohaku absolutely clobber her dad, who'd been coming for him with fists flying. The younger man had left.

Kohaku turned to Senku, cheeks still red and a scowl on her face, hair breaking free of that fancy updo, knuckles bruised. His very own avenging angel.

"Marry me," was all Senku managed before he passed out completely