End Game by YAMANAKA Hiko

Plot Summary:

After the death of his mother, Itou Katsuya has been living with his guardian, Tooru—a young man who took him in. However, Katsuya struggles with fragmented memories of the past, unable to recall the details of his mother’s death. To make matters even more complicated, he harbors feelings for Tooru that go far beyond what a son should feel for a father figure, making his teenage years a torment of confusion and guilt.

One day, Katsuya encounters a man who claims to have been a friend of his late mother. From him, Katsuya learns a shocking truth—his mother was killed in a hit-and-run accident, and the culprit was never caught. Determined to uncover the truth, Katsuya sets out on a journey to find the person responsible, all while wrestling with his forbidden emotions for Tooru…

(Related: End Game Vol. 2)