Mantle is a male of a very-short stature. His body is small in size, but big in belly, with visible chest-hair. In comparison to his small body, his head is huge, and its shape resembles that of a Chinese Buddha statue's. Mantle's face has very slanted and baggy eyes, with elongated eyelids. His hair is black, and he also spots a beard.
Mantle's clothing consists of a black ragged peasant tunic, with a piece of rope acting as a belt.
Hearing Senku's plan to rig the village games and wanting to assure a victory for Magma, Mantle follows after Suika and ties her up. He tells the Kingdom of Science followers that Suika is drowning and someone needs to save her. Although it was clear he was lying, Kohaku wanted to make sure Suika wasn't in danger. She proceeded to chase after Suika, even after much reluctance from Senku and the others. Chapter 34 pg 13-16
Due to Mantle's plan, Kohaku was absent for her round in the Village games, resulting in her loss. Mantle was successful in his plan.
Mantle had the ability to catch up to Suika, who herself is pretty speedy. Mantle was able to have a balanced spar with Chrome in the village games. He eventually forfeited, but not because he was in a bad position or shape.
- His name is a reference to the Earth Mantle which is the Middle layer within the Earth interior.