Kubota Tamotsu is a university student who is burdened with a debt. He is a dull student and spends most his time doing part-time work. One day, in an attempt to reduce his debt, he falls into a scam. He is now in the biggest crisis of his life. At that time, he meets a criminal tools dealer and is saved by him. They begin to work together in the criminal world of Ikebukuro, which is dominated by three groups: Jinbokai yakuza group, Gozugumi yakuza group, and the Taiga group. The latter group deals in specials frauds like bank transfer scams. In addition to these, a mysterious duo appears in the criminal world of Ikebukuro.