Okamoto Kyoudai no Baai

A forbidden sibling BL story about a younger brother who lusts after his older brother! Whenever Haruto comes home drunk, his younger brother Riku has to take care of him. When he's drunk, Haruto sleeps deeply and never wakes up until the morning. Taking advantage of this, Riku would take Haruto to his room and masturbate repeatedly. Over time, Riku began to escalate his actions more and more... (Source: Charles Comics, translated)