This volume is a collection of 3 short stories.

The first one is Ningyo Ouji, the tale of a mermaid, or rather merman, who falls in love with a human woman.

The second is Kimi ni Okuru Hana wo Tsumu, where a boy who died loved a girl so much that he possessed her manager's body.

The third one, Sekai wa Futari de Dekite Iru, features a nympho succubus and a...priest!?

This is Yoshihara Yuki for you. Cute, funny and smuttylicious!

[Source: Baka-Updates Manga]