Crossover fandisc with side stories featuring heroines from Komorebi ni Yureru Tamashii no Koe and Mune Kyun! Heart de Koi Shi-te-ru ~Onii-chan Motto Daisuki~. There is also a mahjong minigame and Uno-styled card game where the points earned can be used to unlock extra CGs and BGM mode, as well as various other extras including wallpapers, system voices, desktop icons and a clock application from the in-game shop.

All of a sudden your twin little sisters return! The setting is a cafe that the protagonist's friend is having him run. That's where his twin step sisters come to live with him until graduation. The older sister is the subdued Chiyori, and the younger sister is the cheerful and energetic Chika. Both of them have feelings for the protagonist. Whenever he pays attention to one, the other gets jealous and sulks. It might seem like an envious situation from the outside, but it's a tough way to live! [Translated from [url=https://unisonshift.amusecraft.com/products/project4/project4.html]the official website.[/url]]