Naoto Rindo is successor of his clan, a wealthy family that holds a good luck ritual every third generation. It's Naoto's turn, and he must produce an heir before the ceremony takes place. The only problem is that his fiancée is dead!

Failing to impregnate his sister-in-law, he is now instructed to try with her three sisters. Naoto leaves home and moves into their apartment, where one of the sisters protests the arrangement completely. Things aren't smooth sailing with the other sisters either, as one bursts into tears when Naoto tries to mount her. The next night however, she's more willing.

Naoto gives the youngest sister, Ayumi, a sex-ed class that quickly evolves into oral; she spits his seed out into her hands, then sniffing it ponders "smell of a chestnut flower?" And laps it up.

Ringetsu is a very well made hentai and Naoto is a likable lead. Although it's only 28 minutes, they've crammed it with plenty of sex and character development.

Retailing: Nice sex and a well-scripted plot; it's a series customers will want to follow.