Kusuburu Kemuri no Nare no Hate

Overview

When Masaki goes to college, he ends up staying with his cousin Haruomi, whom he admires and has a crush on. However, when he meets him again for the first time in several years, he has completely changed from the older brother he admired to a sloppy old man. He is shocked by his appearance, but he remains kind to Masaki, and his feelings for him grow stronger once again. However, no matter how hard Masaki tries to tell him how he feels, Haruomi stubbornly refuses. Masaki is frustrated that he can't even accept his words, but he can sense that Haruomi is indecisive... (Source: Core Magazine, translated)

Source: AniList