9-Nine
9-Nine is a Japanese adult visual novel series developed and published by Palette. It was released for Windows in four episodes from April 2017 to April 2020, with a final episode released in April 2021. It was later ported to the PlayStation 4 and Nintendo Switch in June 2022. An English version of the visual novels was released by Sekai Project from February 2019 to March 2021. An all-aged extra episode was released in April 2021. A manga adaptation with art by Izumi Kawachi has been serialized online via Futabasha's Gaugau Monster website since October 2021. An anime television series adaptation produced by PRA, titled 9-Nine: Ruler's Crown, aired from July to September 2025. A spin-off to the visual novels, as:9-nine- ARTEISIA, has been announced as being planned for release in 2026.
Plot
Shiromitsugawa City is a sleepy college town consisting of various high schools. Living by himself away from his family, Kakeru Niimi enjoys a peaceful life as an ordinary student until a major earthquake shatters the sacred artifact at the local Hakuda Tsukumo Shrine.In the wake of this event, where Kakeru's world is now connected to an alternate world, artifacts that awaken superhuman abilities begin to show up in young men and women in the town, and one such Artifact User emerges as a serial killer.
Kakeru is approached by his classmate Miyako Kujo to track down this serial killer, and in doing so, becomes embroiled in the ensuing chaos between the Artifact Users.
9-nine - Kokonotu Kokonoka Kokonoiro
The first instalment in the series focuses on the first of the four heroines, Miyako Kujo. After finding a petrified human in their college town, Shiromitsugawa City, Kakeru and Miyako work together to investigate the culprit behind this incident. This game can be played on its own without knowledge of the other series instalments.
9-nine - Sorairo Sorauta Soranooto
The second instalment in the series focuses on the second heroine, Sora Niimi. The story branches off from the first game, Kokonotsu Kokonoka Kokonoiro, and focuses instead on the romance between Kakeru and his sister Sora while they work with Miyako to track down the Artifact User petrifying people in the town. This game can be played on its own without knowledge of the other series instalments.
9-nine - Haruiro Harukoi Harunokaze
The third instalment in the series focuses on the third heroine, Haruka Kosaka. The story branches off from the second game, Sorairo Sorauta Soranooto, and focuses on the budding romance between Kakeru and Haruka. Kakeru's group runs into the Artifact User organisation Rig Veda, who appear to oppose their efforts to investigate the serial killings. This game can be played on its own without knowledge of the other series instalments.
9-nine - Yukiiro Yukihana Yukinoato
The fourth instalment in the series focuses on the final heroine, Noa Yuki, branching off from the third game, Haruiro Harukoi Harunokaze. Having uncovered the mastermind behind the incidents, and realizing Noa's Artifact is the key to defeating the mastermind, Kakeru divulges everything he knows about the matter. Together, they oppose the mastermind and uncover the final secrets behind the Artifacts that arrived in their world.
Due to the story structure of this game, it is strongly recommended that this game be played only after completing the previous three games.
9-nine '- Shinsho'
The final instalment in the series ties up loose ends from the previous four chapters with after-story scenes for each heroine. There is a new scenario featuring a story that is yet to find salvation, the final, unfinished task Kakeru has yet to complete.
It is strongly recommended that this game be played only after completing all previous games.
Characters
;Kakeru Niimi;Miyako Kujō
;Sora Niimi
;Haruka Kōsaka
;Noa Yūki
;Sophitia
;Satsuki Naruse
;Yoichi Fukazawa
;Renya Takamine