Yakuza Reincarnation manga volume 4 features story by Hiroki Miyashita and art by Takeshi Natsuhara.

After kicking up some chaos in Daniemi, the gang is back on the run. They set sail for the secret society of Dunia. This smooth ocean voyage is quickly interrupted by pirate attacks, more dark-kin, and a mermaid girl gang. Ryu joins forces with these foul-mouthed fishy females to bust some heads!