The Grisaia series began with the Le Fruit de la Grisaia (The Fruit of Grisaia) visual novel by Frontwing which featured character designs by Akio Watanabe and Fumio. This was followed by two sequel visual novels - Le Labyrinthe de la Grisaia (The Labyrinth of Grisaia), and Le Eden de la Grisaia (The Eden of Grisaia).
The original game takes the form of a romance visual novel centered around the protagonist Yuuji Kazami. Yuuji is actually a hitman working for a Japanese government agency but is bored with killing for a living and wants to live a normal schoolboy life so transfers to Mihama Academy. There are only five other students, all girls, and the school is kind of like a prison. Yuuji therefore has five potential love interests to choose from including: Yumiko Sakaki , Amane Suou, Mitsuru Matsushima, Makina Irisu, and Sachi Komine.
Grisaia has also been adapted into two manga series: The Fruit of Grisaia: Sanctuary Fellows written by Eiji Narumi and illustrated by Shu Hirose which was published in Champion Red Ichigo Magazine, and The Fruit of Grisaia: L'Oiseau bleu written by Jun’ichi Fukasaku and illustrated by Taka Himeno serialised in Monthly Comic Blade (later Comic Garden). The Grisaia series was also adapted into a hit TV anime by 8-bit.