18+ Chinchin Kemokemo

Mui-kun always had the animal magnetism... with animals. Unfortunately, it never worked with girls until his childhood friend Yuzuriha suddenly began to take on various animal aspects, starting when she offered a dance to the mountain spirit as a resident shrine maiden. Now she involuntarily takes on the animal spirit whenever she comes across one, most of whom disdain the confinement of human clothing...

(Source: ThePaulBunyanTrophy)