A private banker is a specialist who give asset management and asset building consultation to high net worth individuals.  Koichi Anno (Toshiaki Karasawa) is a highly skilled private banker hired by Takehiro Tenguji (Isao Hashizume), president of Tenguji Aina Group with a 700-billion-yen asset. His first request is to save Takehiro’s beloved dango store.

Kumiko Iida (Honami Suzuki), president of the dango store, consults banker Naoya Todo (Yoshihiko Hamada) about a loan to keep her store running and is suggested to make an investment. Having no financial knowledge, Kumiko is surprised to receive a large dividend immediately. With Todo urging to make an additional investment with the loan money, she does so… but soon after the company she invested in goes bankrupt, leaving her with a 500 million yen debt!

Devastated, Kumiko tries to jump off a building when Koichi appears in front of her to notify Kumiko she fell for an investment scam and proposes of getting back the 500 million yen. Although Kumiko is highly suspicious of Koichi, a complete stranger, she has no other choice but to trust him.