In the anime
He first started out as Nate, until Black Jibanyan and Black Komasan came into his room, and used the Black Yo-kai Watch to turn him into Kemushi-otoko in EP156. Ever since, he's been hanging out with them all the time.
In EP159, when Kemushi-otoko, Black Jibanyan, and Black Komasan got hit by Eddie, Kemushi-otoko told the Black Yo-kai Watch Eddie says Watches are girly wristbands which caused the latter to turn Eddie into Hae-otoko, then Kemushi-otoko made a scary face causing the bug Yo-kai to flee, Kemushi-otoko used his scary face for the first time when approaching Hae-otoko.
In the games
Unlike the other Kuroi Yo-kai, Kemushi-otoko does not appear in the games.
Kemushi-otoko literally translates into Caterpillar Man
- His medal comes with the Black Yo-Kai Watch toy, along with Black Jibanyan's medal.