The apartment was cozy, with a small balcony overlooking a mossy courtyard. The living room and kitchen were sunlit, but the bedroom, a narrow room at the back, carried a chill. Inside a dusty drawer of the kotatsu (heating table), Aiko discovered a faded diary. Its pages belonged to a girl named Jun Kiriya (JK), a high school student who’d lived there 20 years prior. Her entries spilled out a tragic tale: she had been documenting strange shadows in the apartment, and her final entry read, “The mirror sees them. They came for me. I’m not alone, but they can’t see that, can they?”