蒼碧の選定 (Sapphire and Emerald: The Selection)

"GMless murder mystery for exactly 6 players. Set in a sealed mansion in rural 1994 Japan, players investigate a killing that occurs during an ancient family ritual. Each player receives a personal handout with unique knowledge, goals, and secrets. Gameplay proceeds through timed investigation and discussion phases, supported by a smartphone-based clue discovery system. The game culminates in a simultaneous-action phase where every player's choice shapes the final outcome. One scenario, one experience — once played, it cannot be replayed."

-from the publisher