Uchiki Komori no Hikikomogomo Seikatsu

Komori believes an asteroid struck Earth because he wished for the world's destruction. Feeling responsible, he's been holed up for seven years. But when his childhood friend Sora reaches out, he finally decides to step out into the world...! A shy Komori's coming-of-age romance story as he leaves his room and finds happiness!

(Source: Comic Fuz, translated)