In the beginning, it was Shouyou who brought them together. Kenma had been reluctant but Shouyou had insisted and so Kenma had relented. Nishinoya Yuu scared Kenma, both on and off the court. On the court, Yuu was so intense and determined that Kenma always half-expected him to end up killing someone over a call or something. Off it, Yuu was social and loud and energetic, everything Kenma hated, unless it applied to Shouyou. There was nothing about Shouyou that Kenma could ever see himself hating.
The first few coffee meet-ups had been awkward, at least for Kenma. He sat in the corner of the booth, sipping quietly on his black coffee, and listened to Shouyou and Yuu chatter about this and that and everything in between. It gave him a headache, if he was honest, but he didn't want to start playing his DS for fear of being asked a question and not having an answer. He only ever had that sort of concern around Shouyou's friends; he was afraid that if he embarrassed Shouyou in front of them then Shouyou would abandon Kenma for someone better. Shouyou reassured him countless times that that would never happen, but Kenma wasn't convinced. Not really.
Within a year, Kenma realized that Yuu had the same appeal as Shouyou did, energy and all. That realization scared the shit out of him because he couldn't be falling in love with someone else. He couldn't be. Shouyou was too perfect.
Kenma had thought that falling for Yuu would mean that his feelings for Shouyou would fade, but they didn't. He was just as in love with Shouyou as ever, but he was in love with Yuu as well. It was a disconcerting feeling and Kenma didn't feel right keeping it a secret. He told Shouyou – mumbled it, really – with tears in his eyes, afraid of the rebuttal or the abandonment that, at the time, he was sure to come. Instead, Shouyou grinned brightly, let out a relieved sigh and hugged Kenma tightly.
"Me too," he had whispered in Kenma's ear, "I love him, too."
At first, Kenma hadn't thought that Shouyou understood what he was saying. But then Shouyou started talking and Kenma knew that Shouyou understood perfectly. A wave of relief so strong it had almost been dizzying had washed over him then; he wasn't the only one and he wasn't somehow broken.
They had asked Yuu out together. Yuu had seemed confused to start, but then, once he started realizing what was going on, he had grinned. Kenma had been afraid that he'd laugh, that Yuu would yell at them and call them freaks and start ignoring Shouyou. Kenma knew he would've hated himself if Yuu had alienated Shouyou because he knew that Shouyou and Yuu were close. Kenma wanted their friendship to at least still be intact if Yuu didn't want to date Shouyou and Kenma.
But Yuu did want to date Shouyou and Kenma. He had accepted immediately, and that had been that. It had been awkward and strange at first, being in a polyamorous relationship, but they got the hang of it eventually. Two years later and they were able to exchange I love you's freely amongst each other, even Kenma. It was a surprise to Kenma, since he had never been very open with those words even around close family. Yuu and Shouyou both knew this and didn't call attention to it, but Kenma knew they noticed every time he told them he loved them because they would exchange small, purely happy smiles that made Kenma's insides warm.
In the end, it was Shouyou who tore them apart. It started with a phone call that Kenma had only ever imagined would happen in his nightmares. It was Yuu who picked up, since Kenma was too busy worrying and being paranoid; he thought his concern was baseless.
Kenma hated it when his paranoia was right.
The first clue that something was wrong was when Yuu's smile vanished. Yuu's smile never fell. Even on the rare occasions that he cried; he still had a tiny, sad little smile on his face. Yuu's smile was permanent, but during that phone call, it slipped from his face completely and left it blank with horror.
The second indicator was Yuu's weak, stuttered, "W-what?" For one thing, Yuu wasn't the sort of person who would ever ask another person to repeat themselves, whether he had heard them or not, because he didn't want to be a bother. For another, Yuu's voice was never quiet or shaky, and certainly not both at the same time, but it was both in that moment. Kenma was afraid. There was only one thing that Kenma could imagine would make Yuu sound like that, and Kenma definitely didn't want that.
Yuu had tears beading in his eyes by the time he hung up the phone. Kenma couldn't muster the courage to ask what had happened through his anxiety, but Yuu must have been able to see the question on his face.
"There was an accident," Yuu explained quietly after inhaling and exhaling, slowly and shakily. "Th-they… They want us to go identify a body."
Kenma's heart plummeted to his toes. The last thing he ever wanted to do was identify Shouyou's body, especially if it really was Shouyou's body. Yuu had already started crying, gasping heaving sobs that shook the entirety of his tiny frame. Kenma held Yuu until he calmed down; although Kenma didn't really want to touch or be touched at the moment, he knew that it grounded Yuu. Kenma wanted to make sure Yuu was calm for when Shouyou came home, because if he saw Yuu cry, Shouyou would worry unnecessarily.
Kenma knew he was in denial. He knew it, just like he knew that he was deluding himself by thinking that they had misidentified the body. The entire drive to the hospital, silent and tense, was spent trying to fight off the knowledge that Shouyou would never come home again. He tried and failed to convince himself that of course it wasn't Shouyou, that it couldn't be Shouyou. It was just some stranger who happened to have the same small body, the same cute freckles all over his nose, the same bright hair, and the same shining eyes.
Kenma tried not to think about those eyes, dull and lifeless.
They were met at the doors by a grim-looking police officer and an equally grim but slightly more sympathetic doctor. Yuu clutched tightly to Kenma's hand; he had burst into tears again the moment he set foot in the morgue.
Kenma didn't start crying until the sheet, blooming with fresh bloodstains, was pulled away from Shouyou's face. It was definitely Shouyou, despite what Kenma tried to tell himself. No one else could have hair that still curled and stuck out like a pincushion even after half their skull had been broken off. It was bloody and gory and gruesome; Kenma hid Yuu's face in his shoulder by instinct, trying to keep his boyfriend from seeing the grisly remains of Shouyou even as he himself couldn't tear his eyes away. Shouyou looked so different, broken and bloody and ripped half to shreds, but it was still so obviously him that it hurt.
The funeral was worse. Standing hand in hand with Yuu beside Shouyou's grave was when the realization that Shouyou was gone and never coming back fully hit Kenma. He crumpled to his knees, sobbing and choking on Shouyou's name. Yuu sank down beside him and held him close, even though Kenma needed Shouyou, not a hug. The only thing that would ever fix anything ever again, it felt like, was Shouyou, and that was no longer a possibility.
It was harder for them after that. Shouyou had been what kept them together and with him gone, their differences seemed more obvious and more numerous than their similarities. Kenma's anxiety got steadily worse as Yuu spent more and more time out of the house, sometimes leaving for days on end without a word to Kenma as to where he was or when he'd be back. When Yuu was home, he and Kenma fought more often than not, leading to more anxiety and more time apart. It was a vicious cycle.
What happened next was inevitable, really. Yuu came back, his eyes dull and his hair down like it had been since Shouyou died and announced that he was leaving. Kenma watched numbly as Yuu packed his things and dragged his bags out the door, planting one last kiss on Kenma's cheek before the door clicked shut behind him.
The sound shattered something in Kenma. He curled on the couch, clamping his lip between his teeth so hard that it bled in an attempt to keep quiet as he sobbed. Things had been getting worse and worse and Kenma knew that the breakup was the healthiest option for the both of them – they needed to move on eventually – but that didn't mean it didn't hurt. He had had the best thing in life and then both of the people who he thought that he would be able to depend on for the rest of his life had abandoned him. Kenma cried, Shouyou's favorite blanket clutched to his chest, and tried not to drown in the knowledge that he was alone again.