The story of the series centers around Yuuji Kazami, who enrolls into Mihama Academy in an attempt to live a normal life from his "job". While taking residence, he meets five girls, each with a reason for enrolling into the school, and later learns from their circumstances that his so-called "normal life" is anything but. Most of the series has Yuuji interact with the girls and developing a relationship with them, and all the while, also delving into a bit of his own shady past.
The series is composed of several installments:
The Main Trilogy
- The Fruit of Grisaia (Grisaia no Kajitsu): The first entry in the series, Fruit is mainly a romance eroge visual novel which focuses on Yuuji living a normal life and developing a relationship with the girls. Released in Japan on Febuary 25, 2011, and worldwide on May 29, 2015.
- The Labyrinth of Grisaia (Grisaia no Meikyuu): The second entry in the series, Labyrinth is a re-telling of the first visual novel's scenarios with the girls as well as adding a main story focused on Yuuji's past. Released in Japan on December 29, 2011, and worldwide on June 22, 2016.
- The Eden of Grisaia (Grisaia no Rakuen): The third entry in the series and the final entry of the main trilogy, Eden is a direct sequel to Labyrinth with a lot of action involved as well as some science fiction elements. Released in Japan on December 21, 2012, and worldwide on April 28, 2017.
Other Main Installments
- Grisaia: Phantom Trigger: The next installment in the main series and the sequel of Eden. Phantom Trigger is an all-ages kinetic visual novel which features a new cast of characters and a plot centered around training students for national security purposes. It was released on April 28, 2017. Instead of branching plot lines with one narrator, the story is divided by a succession of volumes with two main characters doing the narration.
- Grisaia: Phantom Trigger The Animation: An anime adaptation of Phantom Trigger, which is a sequel of the OVAs. It adapts the fourth volume onwards.
- Grisaia: The Hundred Fruits of Gathering (Grisaia: Shuuketsu no Hyakka) a mobile game to be released in Summer of 2026. Another sequel to Eden, featuring the rise of a terrorist organization that may have ties to Yuuji and the girls, as well as a group of young ladies who claim to be Yuuji's daughters from twenty years in the future.
Spin-Offs
- Idol Magical Girl Chiru Chiru Michiru: A spin-off Magical Girl kinetic visual novel staring Michiru Matsushima as the main character. It parodies numerous aspects of the genre and is not directly tied to the continuity of the main series. The spin-off comes in two parts. The first part was released in Japan on August 28, 2014, and the second part on December 26, 2014. Both parts were released worldwide on August 29, 2015.
Side Stories
- The Leisure of Grisaia (Grisaia no Yuukan): A short side-story to The Fruit of Grisaia, it was originally a bonus exclusive to the DVD release of The Eden of Grisaia in Japan. It centers around the heroine Michiru Matsushima as she comes up with attempts to form club activities in Mihama Academy to make the school more interesting. Released worldwide on May 18, 2016.
- The Afterglow of Grisaia (Grisaia no Zankou): A short side-story to The Labyrinth of Grisaia and another DVD bonus exclusive in Japan, it sheds more light onto Yuuji's past and his relationship with his master Asako. Released worldwide on July 20, 2016.
- The Melody of Grisaia (Grisaia no Senritsu): Another short side-story to The Labyrinth of Grisaia and a bonus exclusive of Front Wing's other visual novel work Hatsuru Koto Naki Mirai Yori in Japan, it gives more insight onto Yuuji's job and profession. Released worldwide on December 15, 2016.
Tropes applying to the series as a whole:
- All Women Are Lustful: All of the girls are portrayed as having dirty thoughts on a regular basis, far moreso than the male main character, Yuuji. Amane is the most obvious example, but there are numerous discussions among the girls regarding each other's porn habits or masturbation fantasies. In nearly all cases and routes, it's the girl who initiates sex between Yuuji and herself. It's later shown that Yuuji has had previous sexual experiences, and not all of them positive or healthy, which may explain why he's not as eager for sex as one might expect from a guy his age.
- Breakout Character: Matsushima Michiru became somewhat of a fan favorite. She was the lead of the The Leisure of Grisaia side story, and the third main novel, Eden seemed to weirdly favor her among the love interests, despite the story following a kind of "harem" route and a romantically non-committed protagonist, a prominence she even lampshades. Most importantly however, she received her own spin-off game, the magical girl themed Idol Magical Girl Chiru Chiru Michiru, which takes place in an alternative, much more lighthearted and comedy focused Grisaia universe.
- Giving Someone the Pointer Finger: Michiru favors pointing at others throughout the visual novels . She usually does this just for emphasis.
- Stock Light-Novel Hero: Yuuji Kazami is a Decon-Recon Switch of the trope. He fits most of the criteria: incredible skills, a growing Unwanted Harem, a stoic persona, a compulsion to help others, and an average appearance. However, his backstory reveals the circumstances under which he gained most of these. He suffered years of Parental Neglect in favor of his far more intelligent and talented older sister, which turned into abuse from his father after their cash cow died, culminating in his mother's murder. Yuuji killed his father in retaliation before being picked up as a Child Soldier by a terrorist who also sexually abused him. Some time later, he was then trained and raised by a female mercenary, who also took him as her lover before she, too, died and left him all alone. By the time the series begins, Yuuji is a suicidal, broken shell who wants to lead a "normal" life for a while and only helps the girls that eventually form his harem because he promised his deceased master that he'd help five people in need before he killed himself. However, the various games and the anime have numerous ways that Yuuji can finally earn his happy ending and live happily with some, or all, of his harem.
- Walking Spoiler: Idol Magical Girl Chiru Chiru Michiru has Thanatochu, Kazuki's magical mouse companion that's helping her collect the Chaos Medals. He turns out to be the Big Bad, who used Kazuki to collect the medals and steals her wish for him to regain his true power, revealing himself to actually be an entity called Ghost.