Sun-Ken Rock

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 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.

As the story progresses, the Sun-Ken Rock Group becomes bigger as they recruited new members and take over other gangs' territories and investments.

Ironically, Yumin was groomed to become an advanced plant in Korea to help her yakuza group lay the foundations to expand their hold into South Korea; due to Yumin's refusal to join the "family business," their plans were stalled as various members either tried to take her back to Japan or try to get her back into yakuza control.

Written and illustrated by Boichi, Sun-Ken Rock was serialized in Shōnen Gahosha's seinen manga magazine Young King from April 24, 2006,[a] to February 22, 2016.