Jukkakukan no Satsujin

Both stories trap a group of characters in an isolated location (a snowy school vs. a remote island), cutting them off from the outside world. This forces the focus onto group dynamics, suspicion, and hidden secrets.
They also share a strong emphasis on psychological unraveling. In White Christmas, the question is about human nature and whether people are born monsters, while Decagon leans more into classic deduction. Both though build the same eerie feeling that danger is coming from within the group.

Soshite Daremo Inakunatta and Jukkakukan no Satsujin feel similar because there’s a shared “Agatha Christie” structure: a limited cast, an isolated situation, and a steady breakdown of order as fear and suspicion take over.

- Modern take on classic island/locked mysteries
- Very close to Jukkakukan no Satsujin structure because the main character/student tries to solve the mystery

Closed setting - characters are trapped (training center in kdrama/ isolated island in j-movie)
Ensemble cast - a group where everyone could be a suspect
Constant suspicion - trust breaks down as events unfold
Psychological tension - fear, paranoia, and mental pressure drive the story
Dark, eerie atmosphere - unsettling tone throughout