Underground casino "Paradise," like all casinos, has a healthy amount of seediness. Toru Shintani, a dealer, suspects his dealer colleague Kikuchi is stealing from the casino and confronts him. Little did Shintani know that this was the first step into his quick descent into the shady side of "Paradise." To keep an eye on Kikuchi, Shintani opens up his home to the poor thief and plays a make-do go-between for Kikuchi and the yakuza in charge of the casino. Shintani soon finds out that dealing with the yakuza won't go as smoothly as dealing for them.

(Source: Futekiya)

When Shiba Daisuke confesses to his delinquent upperclassman Akiyama-kun in front of all of Akiyama's friends, getting beat up and ridiculed would maybe be understandable. But the events that follow are nowhere near what any of them would expect.
(Source: MU)