Kotoko (movie, 2011)

Suffering from double vision, a single mother (Cocco) tries to take care of her baby in the grip of terrifying hallucinations. Experiencing a nervous breakdown, she is deemed unfit to take care of her child and has it taken away from her. The only respite the mother has from her visions is when she sings. An award-winning novelist (Tsukamoto) overhears her singing whilst riding the bus and the pair subsequently develop a volatile relationship.