It sort of blows my mind that the author went out of their way to specify that Kuuya and Suika were not dating in the epilogue, and that Kurenai did not give up yet.

Seeing that childhood friends basically never win, I was pleasantly surprised when the tide started turning in her favour. Why you ask, she basically spent more than five years hiding her feelings every day for Kuuya's sake, as well as protecting him from harm the whole time. She definitely deserved that win.

After having her confess her feelings, having him overcome his trauma by the same token, and having both of them exchange a kiss, literally linking their blood stained hands together (and probably trading some viruses too), it is hard to not want them to end up together. (Granted, the kiss was a little one-sided, but still!)

It is true that nothing would have happened without Kurenai's meddling, but that was exactly her role: breaking the status quo. She managed to grasp plenty of happiness by finally realising her humanity as she came across her first heartbreak. She even acknowledges that she sort of butted in into the two's piled up years of history. Her crying scene was bitter, but at the same, should have been a beautiful conclusion to her growth. It is sort of miserable, ending the epilogue on her confessing...

Notwithstanding, my copium-free opinion is that Kuuya and Suika would end up together, considering how her yandere level is second to none.