Koichi Anno (Toshiaki Karasawa), a private banker for Takehiro Tenguji (Isao Hashizume), president of Tenguji Aina Group, earns Takehiro’s deep trust after saving Kumiko Iida’s (Honami Suzuki) dango shop from peril. Koichi receives Takehiro’s next request. Sensing he doesn’t have long, Takehiro is sure that there will be a dispute amount the Tenguji family over his 700 billion assets. “I want you to protect my assets.” Takehiro orders Koichi to his family members as the Tenguji family’s private banker.

That’s when eldest son, Tsutomu Tenguji (Junpei Yasui) falls from the stairs and lands in a coma. On top of that, Tsutomu’s driver witnessed the event and stated that a woman-like figure pushed Tsutomu. Mikoto Tenguji (Mari Natsuki), Takehiro’s wife and the one with absolute authority in the family, orders Koichi to find the culprit.