Kiseru Gankubi

Kiseru Gankubi is a shinobi of Konohagakure.

Personality
Kiseru is a feisty and hot-headed individual, refusing to remain still after being captured, and doing everything in his power to try and escape the secluded room he was trapped in, despite others's insistence that it was meaningless. He also has quite a high tolerance for pain, as despite his hands being swollen from continuously punching a wall, Kiseru himself was visibly unresponsive, confidently saying that it was nothing that effort couldn't overcome.

He is also quite kind-hearted and compassionate, helping Boruto in rescuing the other survivors instead of focusing on saving himself. He also urged Boruto to not get discouraged after not being able to save some of the survivors, claiming they did everything they could, further showing his compassion.

Abilities
Kiseru can utilize the Fire Release nature transformation, being able to spit out a bullet made of fire towards any direction. He is also capable of leaping several feet in the air quite easily, further showing his physical prowess.

Labyrinth Game Arc
While on the Thunder Train, Kiseru and all the other passengers fell asleep and they found themselves in a secluded room once they regained consciousness. Subsequently, Kiseru attempted to break out by attacking the walls, albeit to no success. Then, Kiseru recognized Boruto, revealing himself as a fellow Konoha-nin. Soon, the perpetrator behind their kidnapping, Ōga, revealed himself and explained he wanted to formulate an experiment to how many of them could survive. When they were transported to a different room, with a stone floor was slowly crumbled away, Kiseru helped Boruto save the other survivors by building a makeshift ladder. When some of the survivors died during the "experiment", Kiseru told the distraught Boruto that they did everything they could and not to get discouraged. He and Yatsume then stood by Boruto as he confronted Rokuro for killing Anaguma and an innocent civillian to save himself.