The Yakuza's Bias 2 by Teki Yatsuda

A yakuza enforcer becomes the gang world's biggest K-pop stan in this cult comedy manga that went from webcomic to sleeper hit in Japan! Perfect for fans of Way of the Househusband, Phantom of the Idol, or Spy x Family.

WITH HONOR AND HUMANITY
Ken Kanashiro has taken the vow of brotherhood in the world of K-pop fandom. His devotion and commitment to MNW — the hottest K-pop boy band — inspires many around him, including his rival, Kinji Mizuhara. When Miss Megumi is not able to attend the upcoming concert (or "celebration" as Ken calls it), Kinji jumps at the chance to his bias in person for the first time. With primal fervor, the yakuza fanboys are treated with excellent fan service and become more determined to attend the upcoming handshake to repay their debts.