Sun-Ken Rock is a Japanese manga drawn and written by Boichi. It’s about a guy named Ken who comes from a rich family but lost his parents when he was young because they were involved with bad people called the yakuza. He became known for getting into fights when he was in high school. His main reason for doing anything is his feelings for a girl in his class named Yumin. When he finds out she’s going to Korea to become a police officer, Ken leaves everything behind and tries to go after her. But things don’t go as planned, and he ends up accidentally becoming the boss of a local gang. He tries to keep this a secret from Yumin because she hates gangs. Despite this, Ken’s gang grows bigger and more powerful, taking over other gangs’ territories and businesses. They even become the biggest gang in Korea. Meanwhile, Yumin, who was supposed to help her yakuza group expand into Korea, refuses to join them and causes a lot of problems. As Ken’s gang gets stronger, he and Yumin get closer, but their relationship is always complicated because of Ken’s gang stuff and Yumin’s yakuza connections. Everything changes when Yumin gets kidnapped by her own group, and Ken has to reveal himself as a gang leader to save her from his biggest enemy, Kim Ban Phuong.