In her freshman year of high school, Ryouko Midorikawa discovers her beloved feline, Pow, lifeless in the bathtub. Suspicious of his aversion to water, Ryouko dismisses his demise as accidental. However, that very night, peculiar occurrences begin plaguing Ryouko, signalling the start of her eerie liaisons with apparitions, but also the journey towards the person who holds her heart.