The Black Swallowtails was a Japanese street gang that was active in the Dotonbori district of Osaka during the 2010s. Led by Keita Kuroyanagi, the gang was feared for its acquisition of deadly weapons like swords and knives, and, in 2019, it took advantage of Kazuma Kiryu's defeat of the Red Peacocks and White Knights gangs to incorporate their former members and attempt a takeover of Dotonbori. However, Kiryu bested this combined gang in combat at the Iwao Bridge, and a humbled Kuroyanagi agreed to disband his gang before persuading Kiryu to take him under his wing in the Joryu-kai.