Mizuiro (2003)

Based on the erotic game by NekoNeko Soft. Brother and younger sister-in-law live in the house which parents are often away from. Yuki who is the younger sister is secretly yearning for Kenji who is the elder brother. However, one girl came to show up from the closet in Kenji's room after a certain night. Moreover, her body is transparent, and she looks like the ghost. Her name is Hiyori. She is ...