Wootan To Fumi summary:

Novelist Fumi loves his childhood friend, Woo-tan. Woo-tan curiously sprouts rabbit ears once every month, and during that time, goes to rest at Fumi's house. Woo-tan, who has been candid and cool ever since they were little, now has a juicy body. Fumi started writing novels to sublimate his desire for Woo-tan, but somehow, they started living together...!?