Asa kara Zusshiri Milk Pot 2 Liter: Futanari Shimai no Dosukebe Roshutsu Senzuri@Akihabara

The story takes place after the wedding event between the two main characters. At long last, Iori now can, once again, get together with her sister, Kaori, who is working as some kind of sex slave.

After their reunion, the two sister spend their time with each other. They are having fun, but for some reasons, Iori goes insane, and she decides to work as a "maid", together with her sister.

(Source: VNDB)