Kiss Kara Saki wa Ad-lib de

Ryotaro, a popular actor whose personal life is a mess, crosses paths with a beautiful young man named Kei, who his girlfriend has just dumped. As they talk, Kei reveals that he often cares for others, sometimes too much, prompting Ryotaro to open up about his own struggles. When a stalker fan discovers Ryotaro's home, he temporarily moves into Kei's room. He finds comfort in Kei's nurturing nature, but everything shifts when Kei unexpectedly sees Ryotaro masturbating one day...

(Source: Frontier Works, translated)