Illegal Mahjong

Japanese mahjong with unlockable skills that let you cheat

AleCubicSoft · Published by OTAKU Plan · Released Jan 11, 2024

Reviews: Very Positive; 80% of 156
Recent reviews: Not enough recent
Players: 0; daily peak, Oct 28, 2026
Steam Deck: Untested
Last update on Steam: 2 years ago; Jan 10, 2024
Minimum PC: DirectX 11 GPU; 4 GB RAM · 1 GB disk; Full requirements

What is Illegal Mahjong?

This single-player board game follows Yuri, a former heiress trying to repay her father's business debts. You play mahjong matches against computer opponents and must finish with the highest score or face game over.

For you if...

+you like anime characters and a fully voiced heroine

Not for you if...

−you prefer games without nudity or sexual content

What players say

80% of 156 reviews are positive

Players praise the mahjong matches themselves. The most common complaint is the lack of a tutorial, with reviewers saying you need prior knowledge of Japanese mahjong.

Screenshots and trailer

Illegal Mahjong system requirements

Minimum: DirectX 11 GPU, 4 GB RAM, 1 GB of disk space.

As published by the developer.

Can my PC run Illegal Mahjong?

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Minimum

OS: 7 / 8 / 8.1 / 10
Processor: 3+ GHz Processor
Graphics: DirectX 11/OpenGL 4.1 capable GPU
Memory: 4 GB RAM
Storage: 1 GB available space
DirectX: Version 11

Does Illegal Mahjong have co-op or multiplayer?

No: single-player only, no multiplayer modes declared.

Single-player

Does Illegal Mahjong run on Steam Deck?

Untested Not yet tested by Valve on Steam Deck.

PC version details

DRM: None declared on Steam
Controller: Keyboard and mouse
Platforms: Windows
Achievements: 8
Steam features: Family Sharing
Languages: Full audio: Japanese. Text only: English, Simplified Chinese, Traditional Chinese.

Does Illegal Mahjong use AI-generated content?

No AI-generated content is disclosed on the game's Steam page.

Self-reported by the developer under Steam rules: it covers AI content that ships in the game, not tools used to make it. Steam page checked on Oct 27, 2026. How to filter AI games on Steam