After a contentious divorce, Yoshimi Matsubara is determined to build a new life for herself and her young daughter, Ikuko. She finds herself struggling with the demands of single parenthood as she tries to secure a job and a new apartment during a fierce custody battle for Ikuko. Yoshimi moves into a dilapidated, eerie apartment building, eager for a fresh start, but almost immediately, strange occurrences begin to beset her. Persistently damp patches appear on the ceiling, and her daughter's new school bag repeatedly gets lost, only to reappear in unlikely places. The building's eerie atmosphere and the neglectful management add to Yoshimi's anxiety, which grows with each unsettling event.

As the stress takes its toll, Yoshimi starts uncovering the building's dark history. She learns of a young girl who lived in the apartment above hers and mysteriously vanished, leaving echoes of her existence - and possibly something more sinister. The water leaks in the ceiling become more frequent, leading to an otherworldly mystery that seems connected to the missing girl. Yoshimi's already fragile reality begins to blur, crossing into a realm where the ghostly and the real intertwine, making her fear not only for her sanity but for her and her daughter's safety as well. The battle to protect Ikuko becomes more than just a fight for custody; it's a fight against an unknown and terrifying force emerging from the shadows of their dark water-stained home.