Yami Shibai 3

Synopsis

Late one night, at a closed swimming pool, a teenage boy, Tooru, sneaks into pool, recalling how his gym teacher announces the prefectural tournament next week and doesn't expect anyone to slack off. He says to Tooru that he expects good results. In the present, Tooru figures that he can't be ready for next week, hence his late night practicing, though he notes how the pool looks creepy. But his remains deterred and dives into the water, awakening something... As he swims through the pool, winning the tournament on his mind, he hears something splashing nearby. Convinced it's just his imagination, he resumes swimming, unaware that he's being followed by black, hairlike tendrils. Finally, he reaches the end of the pool and it's then he notices the black hair in his hands. Looking up, he sees more of the hair in the center of the pool, hair belonging to someone, or something. Terrified, Tooru tries to swim away, but is entangled in the hair and even hears something cackling in the water. However, he manages to get away and exits the pool but when he turns around to face the creature, he sees it looming just under the water. Deciding to skip the practice, he tries to make a run for it, only for more hair to wrap around his throat. A splash is heard and Tooru sees the owner of the hair jump out of the water: a giant fish with a woman's head and glowing yellow eyes. The fish woman laughs as it pulls Tooru under the water.

(Source: Wikipedia)