Toad's Oil

It tells the story of the Yazawa family. Yazawa Takuro is an egocentric high-rolling day trader who likes to boast that he can earn hundreds of millions of yen in one day. He has a charming wife, Erumi, and a teenage son named Tetsuya, who dreams of becoming an astronaut. The family is also joined by Saburo, a good-natured teen recently released from a juvenile corrections facility.
One day, the family's life changes when Tetsuya gets into a devastating car accident and falls into a coma. A chain of events is is then set off by Takuro when he answers a phone call from an unsuspecting girl named Hikari and pretends to be his son.