Mizen Tantei: The Protea Cases

Release Dates
(Switch) Japan
Jul 28 2022
(PS4) Japan
Oct 12 2022
(PC) Worldwide (Japanese)
Nov 7 2022
Japanese Title
未然探偵 The Protea Cases
Official Website

Mizen Tantei: The Protea Cases is a visual novel developed and published by Orange.


Shinjuku, 2023.

The protagonist, Chiharu Izuki, lacks self-confidence due to the trauma of once being kidnapped, and spend her days unable to help anyone at all.

One day, while searching for a missing person at her detective agency job, she comes cross the mysterious app “Protea.”

It was a crime prediction artificial intelligence developed by the Metropolitan Police Department and currently being tested in the Shinjuku Ward.

Guided by Protea’s predictions, Chihari encounters various incidents.

She meets a detective who asks for her cooperation, a mysterious boy who for some reason appears at the scene of the crime, and others.

Chiharu’s new life of cooperative work to prevent incidents before they occur has begun…!


Gather information and deduce how to prevent predicted incidents before they occur. In Shinjuku City, various incidents will occur, such as assault, theft, and murder. The protagonist will team up with the detective agency’s director and detectives to confront these heinous incidents. And their bonds will gradually deepen… This is a game in which anyone can easily joy all kinds of excitement.


  • Planning / Scenario: Mitsue Kaneko
  • Main Illustrator: Misa Sazanami
  • Sub Illustrators: Hitomi Umemoto / Sasaki Egawa
  • Background Music: Sakumamatata
  • Sound Effects Ogawa Sound (Tetsuhiro Ogawa)

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