Tsuyoshi: Daremo Katenai, Aitsu ni wa

Tsuyoshi Kawabata is just a regular convenience store employee in a mid-sized city west of Tokyo. Except... he also happens to be the most powerful fighter in the world. Although he doesn't particularly want to fight, his reputation precedes him, and challengers come from all over the world to test their might against the mythical Tsuyoshi—and invariably end up handily beaten, clutching their battered family jewels in a convenience store parking lot. Should you wish to fight him, he has three rules to minimize inconvenience: 1) You only get one fight. There will be no rematch. 2) You will fight in a secluded area, where you won't be seen. 3) You will tell nobody about it—even if you lose.