My Uncle's Broken Heart and Me

Kaname has always loved his uncle Takashi ever since he was a child. The two have a shared secret: Kaname admitting to liking boys at a young age and Takashi being gay. Though, Kaname has a bigger secret: he likes his uncle Takashi romantically. Kaname knows his uncle would ever only see him as his nephew, and when Takashi moves out from the family one day, Kaname is forced to bury his feelings. Now a high school student, Kaname is living an average life though he still misses Takashi. However, when his uncle suddenly shows up out of the blue, Kaname's buried feelings rise again. He finds himself confessing to Takashi, even offering his first time, and thus starts the complicated relationship between them.

(Source: Futekiya)