Tomohiko was a large man with a powerful build and stern facial features. He had his dark hair tied back in a short ponytail, with the strands spiking outward in many directions. His Hope's Peak Academy uniform was noticeably unique, including overalls, a dress shirt with the sleeves rolled up, and a yellow tie.
Tomohiko appeared to be a quiet and reserved man; despite being visibly nervous, he reacted calmly when Junko Enoshima revealed she had blackmail material on them. Even during the Killing Game, Tomohiko was able to stay calm enough to trick Aiko into lowering her guard around him. However, he also had a ruthless side, as shown when he betrayed and killed Aiko to use as a distraction for Asukasei. When he started to strangle Asukasei, he appeared to have a psychotic grin, though this was likely due to him falling into despair.
Junko Enoshima gathered all of the Student Council and Izuru Kamukura in the old school building and forced them to kill each other. When the killing game started, Tomohiko picked up a knife, only to find himself and Aiko under fire from Asukasei's submachine gun. Pinned down by Asukasei's wild fire, Tomohiko lured a panicking Aiko into a false sense of security by assuring her he would protect her. He then stabbed her in the gut and threw her body at Asukasei to knock him down.
With his assailant briefly incapacitated, Tomohiko ran up and pinned Asukasei down, grinning maniacally as he started to strangle him. However, Asukasei managed to grab the knife that Tomohiko used to kill Aiko and stabbed him in the neck with it. He then proceeded to stab Tomohiko multiple times after that.
When the Killing Game started, Tomohiko tricked Aiko into trusting him, murdering her after she lets her guard down and showing absolutely no remorse. He even appears to take joy in killing his friend; however, this is likely due to the stress of the Killing Game pushing him into despair.
- His given name, "Tomohiko" (供彦), means "companion" (供) and "boy" (彦).
- His surname, "Gōryoku" (豪力), means "magnificent strength", reflecting his build.