Kiseru Gankubi

is a shinobi of Konohagakure.

Background
At some point, Kiseru was helped by Konohamaru Sarutobi.

Personality
Kiseru is a feisty and determined individual, refusing to give up trying to escape despite making no progress. He is compassionate, readily collaborating with Boruto to help the civilian captives survive Ōga's experiments, and urging Boruto to remain positive after some of them died, stressing they did all they could.

Appearance
Kiseru is a fairly tall child of tanned complexion. He has dreadlocks reaching his shoulders tied in a ponytail. He also has stern eyes with blue irises and thick brows. He wears a white undershirt, a grey vest, and grey pants with black sandals.

Abilities
Kiseru is able to use Fire Release, and can jump several feet in the air quite easily. He has great stamina and pain resistance, attempting to break out of his confinement for quite a while, and being unbothered by his swollen hands after trying to punch his way out. He is also good at improvisation, using the railing of a safe platform to create a ladder.

Labyrinth Game Arc
While on the Thunder Train, Kiseru and all other passengers fell asleep and woke up detained in a secluded room. Kiseru attempted to break out by attacking the walls with Fire Release and taijutsu, with no results. He recognised Boruto, identifying himself as a fellow Konoha-nin. Ōga revealed himself as their captor, and announced he'd put them through experiments to test their ability to avoid death, putting them through five tests before they can leave his maze. After the "Collapse" test was chosen, the group was teleported to atop of a brittle stone floor floating above a massive chasm, requiring them to reach a safe platform. He and other shinobi attempted to attack Ōga, who turned out to be a projection. Concerned by the others still on the platform, Kiseru grabbed one of the rope barriers and lowered it as a makeshift ladder for them to climb. He was sad they couldn't save everyone, but assured Boruto that they did the best they could.

Trivia

 * Written as 煙管, "kiseru" is a type of Japanese smoking pipe, while his surname indicates the shank of the kiseru.