In the eye of the public and media, the Nakamoto family is just a business family which traced back for generations. But under their nose, Nakamoto in the 90s were a well reputed assassins in Japan. They assassinate in order of their clients. It was not long ago when they started to act on their own.

As the securities of the warlords, the drug dealers, the wrong doers tightened, they needed their own back up and upgrade their disguise. That's when they came out to public as businessman and use the citizens as their vest.

Yuta was the only son of the 6th Nakamoto pure blood generation. At his teen days, he has successfully assassinated 10 power heads alone. When he approached his 20s, he was removed from his rank in the special squad as the no.1 assassin to focus on his future so that the family line does not end in his generation. If his cousins inherit the Nakamoto Company, they must put an end to their secret.

When he was 2, his parents went to China to carry out an order from the chairman. Unfortunately, his mother was killed on their way back home when their target's superior made an ambush. However, his father brought home an infant he rescued. Winwin later grew up alongside Yuta, to be a young excellent man.