Ryou has a problem. Anytime he enjoys his own company, he wakes up to see his room in complete shambles. He seeks help from a hotline specializing in solving all issues sensual. There he meets Rumi, where it becomes clear that arousal turns Ryou into an actual monster.
These are the characters available:
Natsumi Rumi - 夏見ルミ
Sugiura Ryou (takes extra effort, you need to specify "short hair", "shirt". See the sample) - 杉浦了
Oyuki - おユキ
Maki - マキ
You can also generate a random monster form of Ryou from the OVA.