Narusawa Kei - Tropical Island Maniacs 2 - Hentai Manga

Kei and Akari have gotten into a regular routine of sex, but when she has to go away for the weekend for an overnight field trip she worries he might be lonely without her. She shouldn't worry, though, since the usually quiet Tsuzumi has every intention to keep him busy for the weekend in her sister's place. What will happen when Akari gets back and learns of the two growing closer while she's away?!