Master Detective Archives: Rain Code is a 2023 adventure video game developed by Too Kyo Games and Spike Chunsoft, and published by Spike Chunsoft. The game, created by several members who worked on the Danganronpa series, including scenario writer Kazutaka Kodaka, character designer Rui Komatsuzaki, and composer Masafumi Takada, was first released for the Nintendo Switch on June 30, 2023. An enhanced version was released for PlayStation 5, Windows, and Xbox Series X/S on July 18, 2024, in Japan and October 1 worldwide.

The story centers around Yuma Kokohead, a trainee detective with amnesia, and his shinigami ally named Shinigami investigating an isolated, perpetually rainy city called Kanai Ward, controlled by the Amaterasu Corporation. Through a series of murder cases, Yuma and his supernaturally-powered Master Detective allies aim to discover Kanai Ward's Ultimate Secret and solve the Great Global Mystery. Finding the truth is made difficult when Amaterasu's enforcers interfere with the cases Yuma investigates, which requires him to enter an alternate dimension known as the Mystery Labyrinth, and solve the cases there by gathering the evidence needed to prove the culprits' identities.

Master Detective Archives: Rain Code is a fantasy-mystery adventure game taking place across six chapters. Players control Yuma Kokohead, an amnesiac detective who solves incidents with the help of Shinigami. Gameplay alternates between Kanai Ward in the real world, where the story unfolds, and the Mystery Labyrinth, a dungeon formed from the mysteries surrounding a case.

During each chapter, the player explores the Kanai Ward area, where they can either progress the main story or partake in optional side quests known as Requests. By interacting with objects, speaking with characters, and completing various tasks, players earn Detective Points that increase Yuma's skill level and rewards Skill Points. Skill Points can be used to unlock various abilities that can be used in the Mystery Labyrinth. Additionally, the player can find statues of Shinigami, which can unlock optional dialogues with side characters. When an incident occurs, players search for information and clues, which are converted into Solution Keys for use in the Mystery Labyrinth. Players may also be required to take part in quick time events or minigames, some of which involve the abilities of Yuma's fellow detectives.

Once enough Solution Keys are gathered, the game moves into the Mystery Labyrinth, the spiritual manifestation of each case. Here, the player must use their wits and Solution Keys to solve the various mysteries behind a case. These involve choosing the correct route, answering questions with the correct Solution Key, and reacting to quickfire questions. Occasionally, players will face off against Mystery Phantoms, manifestations of characters trying to hide the truth, in Reasoning Death Match sections. Similar to the Danganronpa series' Nonstop Debate sections, the player must dodge statements shot out by the Mystery Phantom before striking a contradictory statement with the correct corresponding Solution Key. Players are also able to repel certain statements without evidence and call upon an ally's help to shield them from damage. The Shinigami Puzzle segments require the player to spell out the answer to a question by hitting letters on a rotating barrel within a time limit. Clues can be offered by feeding Shinigami a Solution Key, but irrelevant ones will result in less time.

When the true culprit is cornered, the player takes part in the God Shinigami section, in which the player controls a giant Shinigami as she dodges and destroys obstacles laid out by the culprit. Finally, the Deduction Denouement requires the player to fill in panels of a comic summarizing the case. The player has stamina, which decreases if they make mistakes or are hit by obstacles, with the game ending if it is diminished or if the player runs out of time. Abilities unlocked by Skill Points can be equipped to give the player benefits, such as more health or fewer incorrect Solution Keys. At the end of each chapter, players are ranked on their performance in the Mystery Labyrinth, earning Detective Points based on how well they did.

Amnesiac detective trainee Yuma Kokohead awakens at a train station, learning that he is to board the Amaterasu Express, a self-driving passenger train en route to Kanai Ward on an assignment. Due to Yuma's amnesia, he is suspected as an impostor among the Master Detectives on board, who are members of the World Detective Organization (WDO). Zilch Alexander, one of the detectives, encourages Yuma to rest when he starts feeling ill. After being knocked out in the bathroom, Yuma reawakens to find a self-proclaimed god of death named Shinigami, who claims she is visible only to him due to an agreement they made in exchange for his memories. Yuma finds his fellow detectives dead, and is framed by Amaterasu's Peacekeepers for their murder upon arrival at Kanai Ward. Before Yuma is executed by the Peacekeepers, Shinigami pulls him into a Mystery Labyrinth, an alternate dimension formed by the mystery of the case, which the duo traverse to solve the mystery of the real-world murders. Within the Labyrinth, Yuma and Shinigami discover the true culprit behind the murder, a hitman impersonating Zilch hired to sabotage the Detectives' journey. This fails to prove Yuma's innocence, as solving the case kills the true culprit. He is rescued by Yakou Furio, the chief of the WDO's Kanai Ward agency, who acquits Yuma of the murder before informing him Kanai Ward is an isolated city of eternal rain under control of the Amaterasu Corporation.

Yakou takes Yuma to the Nocturnal Detective Agency, now stationed in a submarine due to eviction from the previous site, where he meets four other Master Detectives: Halara Nightmare, Desuhiko Thunderbolt, Fubuki Clockford and Vivia Twilight. The detectives inform him of the WDO’s goal of solving global-scale mysteries using powers called Forensic Fortes which assist their investigations. The WDO's leader, Number One, calls the gathered detectives to solve Kanai Ward’s Ultimate Secret, which will help them solve the Great Global Mystery, but does not provide information on what either of these cases entail.