Hitou Meguri Kakure Yu
Japanese title: 秘湯めぐり 隠れ湯
Type: OVA
Episodes: 2
Source: Visual novel
Genres: Hentai
Studios: Kantou Douga Kai
Producers: Mary Jane
Duration: 14 min per ep
Rating: Rx - Hentai

Mikio returns to his hometown for the first time in half a year. The first thing he sees is the traditional Japanese onsen inn managed by Yukino Chitose, childhood friend and one-time lover.

Despite the passing of half a year, Chitose still possessed a girlish appearance. However, the traditional clothes that she wears brings out a mature and beautiful feel about her.

That night, upon conclusion of his business, he goes in search of Chitose. Hearing her voice, he follows it and comes to an outdoor bath. Peeking through a gap in the bamboo fence, he is stunned to see her with another man...

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