Kumitantei: Old-School Slaughter, Episode 1 review: Make friends, then bring evidence

The big picture

Kumitantei: Old-School Slaughter turns getting to know your classmates into a considerably worse idea than usual. Himari and fifteen other elite students are trapped in a decaying bunker, caught in a killing game where escape involves getting away with murder or surviving everyone else. Friendship still matters, which is awkward when every pleasant conversation may eventually require you to revisit your assessment of the person having it.

Mango Factory and Akupara Games released Episode 1 on April 23, 2026, for Windows through Steam. This review concerns that episode only. As of October 18, the planned six-episode story remains unfinished, with Episode 2 announced for November. Earlier demos and an unrealised plan for a 2025 Early Access launch do not change the actual episodic release. Anyone seeking a complete mystery with all its answers already waiting should keep that distinction close at hand.

A convincing argument needs the right cards

Evidence goes into the Clinical Trial, where the group must identify the killer. Card Battle Debates add deck construction and combinations to the proceedings, as the Steam description explains. Knowing what happened and preparing a useful way to argue about it become related but distinct responsibilities.

That split creates room for experimentation inside a mystery that still needs a particular culprit. The deduction seeks a convincing explanation; the card system offers choices about how to navigate the confrontation. Players who like both can find more to consider than the next chance to point dramatically across the room. The pointing is important, obviously, but preparation would prefer some recognition too.

There is a conceptual risk in letting the argument become more absorbing than the evidence. If your favourite part of a mystery is the clean moment when facts align, additional combat-like systems may interrupt what you came for. If you enjoy theatrical debates with a build to prepare, they supply an extra reason to engage with the social and exploratory scenes beforehand.

Himari had a much more reasonable day job

Himari Sanada works in her family's café and likes video games. Her everyday background provides a recognisable viewpoint for an extraordinary predicament, rather than beginning with an investigator who seems to have arrived expecting everyone else's mistakes. Listening to people was previously useful customer service. Now it may be essential for deciding whether to believe them at all.

That makes the relationship-building more interesting than simply collecting biographies. A gentle person can still need to scrutinise another person's account, and liking somebody does not resolve a contradiction. The premise puts emotional knowledge and reliable evidence close together without allowing them to become the same thing.

The situation also gives gifts a particularly strange context. In most social games, getting closer to someone is an uncomplicated improvement. Here, becoming attached can make suspicion more uncomfortable. You have reasons to want the connection and reasons to worry about what the connection will eventually ask of you.

The bunker has committed to the aesthetic

An alternate 1989 setting frames the anime influences and retro arcade diversions. The pause-menu presentation draws on 1980s manga and advertising, giving the interface a role in the atmosphere. In a text-heavy adventure, those surrounding screens are places you spend time, so treating them as part of the world makes sense.

Bright, playful imagery can make the killing-game premise more disquieting rather than less serious. A cheerful surface does not oblige the events underneath it to become cheerful too. The arcade detours participate in that contrast, though players who dislike tonal interruptions should recognise that the mixture is deliberate. The bunker has room for more than one kind of unpleasant surprise.

The next episode has not arrived yet

The Episode 2 announcement targets November 2026. Expanded free-time battles, a training mode, a card shop and other later material belong to the forthcoming episode, not Episode 1's current features. A publisher development update separates that work from what is already available.

For a mystery, incompleteness is a significant buying consideration. Later explanations can change how earlier clues and relationships matter. Episode 1 offers an entry into that unfolding story, not proof of the entire series' eventual payoff.

Choose it if an ongoing ensemble mystery with deckbuilding debates sounds like a worthwhile combination. Wait if you need every answer available before starting. Either way, its most distinctive idea is already clear: getting to know people can help you argue with them later. It is an unusually alarming reason to make a good first impression.