Sun-Ken Rock

Sun-Ken Rock (Japanese: サンケンロック, Hepburn: Sanken Rokku) is a Japanese manga series written and illustrated by Boichi. It was serialized in Shōnen Gahosha's seinen manga magazine Young King from April 2006 to February 2016, with its chapters collected in 25 tankōbon volumes. The manga has been digitally available in English by JManga (2012–2013), Crunchyroll (since 2014), BookWalker (since 2015), and Manga Planet (since 2020).

The series follows Ken, a high school delinquent turned down by the girl he loved, Yumin, who promptly left Japan to become a police officer in Korea. Yearning to see the girl he loved, Ken dropped out of high school to travel to Korea and become an officer just like Yumin. Though Ken managed to travel to Korea, he found himself unable to become an officer and instead became a poor shut-in with no money or job. After saving an old man from being abused by a group gang members, he was scouted by the head of a local gang led by Tae-Soo Park, who made him the new boss.