Chii-chan's Development Diary

Upon winning a fighting tournament and being crowned the world’s strongest warrior, Peter Grill discovers a downside to his newfound fame. Women of all species, from ogres to elves, are scrambling over each other for his seed to ensure they have the strongest babies possible. Poor Peter just wants to settle down with his lovey dovey fiancée, but he’ll have to outmatch, outwit, and outrun a harem of very determined monster girls to do so!

The story follows Rena Yukuhasahi, a reserved office lady and Ryouhei Hachiya, a businessman and fellow colleague. Yukuhasahi appears to be the most reserved girl in the company, but becomes a super beautiful woman when she dresses up. Flustered in the presence of her transformed self, Hachiya insists on taking her out, only to find themselves in front of a love hotel.

Male student Souta Tsukishima begins working at his family's public bathhouse as a back washer. While concealing her true identity, Souta's classmate Aoi Yuzuki visits the bathhouse. A relationship between the two begins to develop when Souta washes Aoi's back.

Three years ago, the world learned that harpies, centaurs, catgirls, and all manners of fabulous creatures are not merely fiction; they are flesh and blood - not to mention scale, feather, horn, and fang. Thanks to the "Cultural Exchange Between Species Act," these once-mythical creatures have assimilated into society, or at least, they're trying. When a hapless human teenager named Kurusu Kimihito is inducted as a "volunteer" into the government exchange program, his world is turned upside down. A snake-like lamia named Miia comes to live with him, and it is Kurusu's job to take care of her and make sure she integrates into his everyday life.