"Are you up to becoming my guard dog?"

Samejima Yuuji spends his days doing nothing but getting into fights until one day his fight ended up damaging an expensive car nearby. To pay back the loan for the damages, Samejima accepts the car owner, Uotani Shinichi's offer to become the latter's guard dog.

As a collateral for the loan, Samejima also had to accept 3 extra conditions. One is to work as staff at the café that Uotani runs. He felt tricked because this was a lot different from what he imagined his job as a "guard dog" would be but....