Chuuya has a really rare disease called fatal familial insomnia and Dazai tries to spend his last months with him before he dies and Chuuya starts to feel even worse every day, he has only a few months left to live as it's getting worse he starts to see hallucinations, he starts to think that it's snowing even though it's not and the moment Dazai points out that it's snowing in November Chuuya is confused because he thought that it was snowing this whole time. He won't survive till next spring