Popular games built on game engine CatSystem2

A side story for The Labyrinth of Grisaia, this episode takes place just after Kusakabe Asako officially names Kazami Yuuji her successor as number 9029, and details his globe-hopping exploits thereafter. Yet more secret passages of The Labyrinth of Grisaia are revealed within...

A side story to The Labyrinth of Grisaia, this game explores protagonist Kazami Yuuji's past, focusing on his life with Kusakabe Asako, the CIRS agent who rescued him at a young age from a terrorist organization. Secret passages of The Labyrinth of Grisaia are revealed within...

Patisserie "La Soleil", run by Kashou Minaduki, is flourishing thanks to the help of two catgirls: Maple, full of pride and a little on the haughty side, and Cinnamon, an impulsive daydreamer.

This side story to "The Fruit of Grisaia" is a character-driven visual novel featuring some of the same characters. This time, it's Michiru who takes the lead role in this slapstick comedy. A laugh-out-loud side story detailing the Mihama girls' school hijinks.

This is the second season of Amakano, with a new group of heroines in a similar winter setting.

All of humanity has come to share the same dreams. Some nights, a tale of adultery between a teacher and his student. Other nights, a romance between a commoner playwright and a noblewoman actress. Yet other nights, a story of burgeoning love between a truant young man and a teacher-in-training. Again and again people see these same three dreams. Why does everyone now endlessly experience these dreams? This is the story of the girl who's called the world.

Not so long ago, as the urban areas progressed in their development towards being an information society, there were many places in the mountainous area which kept the same olden feeling. Yoshitsugu was a visitor from 100 years in the future who came to the mountain village Akio-mura. He had been labelled as a failure in the ultra-competitive society in the future, so it was unknown how he was able to travel to the past, an opportunity open only to those with high social positions. Yoshitsugu, a "naturally born child" in age of artificial birth, wandered about in the mountains in the dark in confusion. He followed a firefly, which led him to a young girl in a small lake. The girl Iroha took him into her home for the night. Afterwards, he was granted special permission to stay in the village and enjoy life in the village for a little while. He got to know Iroha better, along with the actual visitors from the future, sisters Arika and Yuno, as well as the village chief’s daughter, Kotobuki. It was much different than the time he lived in: he felt soothed by the slow and carefree days. Was it luck that brought him to the past? He thought that even he would be able to accomplish something here, like maybe fall in love with a girl. Their summer love story begins here.

Another time, another "game". 14 people have been confined to small rural village and fitted with exploding collars. Each one also has PDA with a unique ability and a condition to remove the collar. If anyone tries to leave the designated area or fails to achieve the condition in their PDA, their collar explodes, killing them. This is the "game" of death, where mistrust and manipulation run rampant and death is common. But this time there's also a catch, as when the "Rain starts to fall"... Was remade into Rebellions: Secret Game 2nd Stage in 2013.