Gitei to wakazuma: Kinshin furin

義弟と若妻 近親不倫

Also known as 兄嫁の寝床　溺れる義弟, Aniyome no nedoko oboreru gitei

Yamaguchi Maki felt bored with her husband Koichi's linear, monotonous movements, but she moaned and shook her hips, trying to reach a deeper state of ecstasy. The two had only been married six months...This was the second time Yamaguchi Ryo had met his brother's wife since attending their wedding. Having failed his university entrance exams, Ryo had moved from the Kyushu countryside to attend a cram school in Tokyo, and was now staying with his eldest son, Koichi.