However, after being railroaded by a city detective named Guildias, Guys finds himself accused, convicted, and sentenced to life imprisonment for the murder of a man he never met.

The primary goal of the game is for the player (as Guys) to locate evidence and witnesses that can exonerate him of the murder, unveil the true killer, and get him released from prison.

Secondary goals include learning the killer's true motives, finding out the backstory of the murder, keeping Guys both physically and psychologically healthy, and forming a romantic bond with other male NPCs in the prison.

Enzai has also become famous outside Japan, mostly due to its unusually dark and twisted atmosphere, deep and compelling plot, and surprisingly graphic scenes.

[2] Enzai is the first girls-oriented video game depicting blood, rape, insanity, and abuse rather than the more standard romantic "shōjo" scenes.

[3] Enzai was refused classification by the Australian Communications and Media Authority because of sexual violence involving a person who is, or appears to be, a child under 18 years.