Koibito Ijou no Koto wo, Kanojo ja Nai Kimi to.

Yamase Fuyu, tired of his black job, runs into Ito, his ex-girlfriend from college, one day and invites her out for a drink. They talk about their old days and their new complaints, and just as he was thinking that this is a nice kind of friendship, they get carried away by the energy of alcohol and end up having a one-night stand. Fuyu regrets...