MARS Vol. 12 (Kodansha, 2019)

Kira leaves home with her mother's blessing. When Kira goes with Rei to meet his father, she realizes that he is the elegant man who tried to buy her painting of Rei. It comes out that Rei is actually the son of his father's brother, who Rei's mother had an affair with. Rei's father invites Kira to come live at his house with Rei as his fiance until they graduate from high school. As Kira and Rei explore the giant mansion together, Kira learns details about Rei's life, and Rei is also beginning to remember things that he had long forgotten. When Kira and Rei go exploring alone (Kira to Sei's room and Rei to his mother's room) they both discover things that were held secret for years. Kira finds a suicide note painted into one of his paintings, in which he shows his true colors, which are far darker than anyone could've imagined. Meanwhile, Rei remembers things about his mother's illness that shock him?