DTKM-028 I'll let you fuck my mother, so let me fuck your mother.

This is the story of two mother-son pairs. Tatsuo Kirishima, a son who attends a university in Tokyo and lives alone, is accompanied by his beautiful mother, Towako Kirishima, who is eagerly awaiting her beloved son's return from her hometown. Next door, they share a home with their mother, Miho Sakaki, and her two sons, Yohei Sakaki and Yasuhiro Sakaki. One day, Tatsuo takes his girlfriend home as originally planned, but he becomes sexually aroused by his mother, and, after indulging in obscene fantasies, engages in sexual acts with her countless times, ignoring her. At the same time, Yasuhiro witnesses his own mother, Miho, and Yohei having sex. Enraged by their enviable relationship, he sneaks onto the balcony of the next room and witnesses the mother-son incest in the Kirishima household. When Tatsuo comes outside after a night of sex, Yasuhiro Sakaki targets him and proposes a lewd plan to them...