Namanaka Hyaku Percent!: Katamusubi no Shinpa
Japanese title: 生膣ひゃくぱぁせんと！ 固結びのシンパ
Type: OVA
Episodes: 3
Source: Manga
Genres: Hentai
Studios: Studio 9 Maiami
Producers: Queen Bee, Mediabank
Duration: 23 min per ep
Rating: Rx - Hentai

"Shinpa", the practice of having on one's person a shoelace which color signifies his or her preferred sexual fetish. In this way also is one able to search out his/her ideal partner.

(Source: translated and adapted from official site by Cranston)