euphoria (ユーフォリア) is an eroge released on June 24, 2011, made by CLOCKUP. The HD Remastered version was released on April 25, 2015, while the official English translation, made by MangaGamer, was released on November 27, 2015.
Plot
The protagonist Takato Keisuke and 6 others are locked up in these hidden white rooms. His childhood friend Hokari Kanae, classmate Ando Miyako, underclassmen Mikaba Rika, English teacher Aoi Natsuki, classmate Byakuya Rinne, and classmate Manaka Nemu. While still confused about their unusual situation, a "mystery voice" suddenly speaks to them: "A game has now started. In order to escape the room, Keisuke is the "unlocker" and one heroine the "keyhole". With an assigned act, he must "use the key".
After hearing the unreasonable and immoral requirements to win, Miyako gets enraged and snaps on the "mystery voice". Suddenly, the lights go out. The girls scream. The lights come back on, re-illuminating the white room. They see Miyako bound to a grotesque torture device.
"Anyone who quits the game will eat dick."
Her screaming begins in tandem with the electrical current. With eyes wide open in fear, she pisses and shits herself. Everyone else starts freaking out. However, Keisuke seemed to be getting aroused by Miyako’s appearance. That was his secret, his urge to assault and humiliate girls.
Despite this, Nemu could see right through him and knew. Nemu takes advantage, forcing the protagonist to submit to him as she brings her lips up to his: "This is a contract kiss."
Keisuke was surprised by Nemu’s behavior, but he wanted to protect Kanae. He decided for the sake of escaping that he will violate the others.
(source: Necrosis)