Shin Ruriiro no Yuki / Snow Blue

The hentai is based on the video game "Shin Ruriiro No Yuki ~Furimukeba Tonari ni~ (2000)" from studio AIL. 

Makabe Hiroshi has been interested in various scientific inventions for many years and is studying at the Academy of Sciences. He moves into a new apartment that belongs to the parents of his close childhood friend Yoki-chan. Since he is a scientist, rumors that the apartment is haunted do not scare him, and the low rent becomes a huge plus for a simple poor student. Immediately after moving, Hiroshi decides to throw a party and invites Kotobuki, Yoki-chan's older brother. But the preparations did not go very smoothly, and due to an explosion of some electronic components, a hole appeared in the floor. There Hiroshi discovers a strange vase, from which a snow fairy Ruri later appears. Who is she, this beautiful maiden?