Hardboiled Cop and Dolphin

is a Japanese manga series written and illustrated by Ryuhei Tamura (creator of Beelzebub). It was serialized in Shueisha's Weekly Shōnen Jump from June 2020 to June 2021. The series was published digitally in English by Viz Media.

Plot
Trouble-making police detective Boyle Samejima, who is not averse to follow the book to get the job done, is transferred from Shinjuku, Tokyo to the laid-back Ogasawara Islands. Now at the Anegashima Police Department, Samejima investigates the bizarre unsolved case of "The Cult of the Sea" (海の教団), where a religious cult who worshiped a little girl as their oracle suddenly vanished. That little girl, Chako, has recently returned with a humanoid dolphin named Orpheus, whom she calls "Papa." Orpheus joins the police department on the same day as Samejima, as his partner and superior.