Tetsu stands among Hiwou's younger brothers within their family group. He flees the village alongside Hiwou, siblings Shishi, Machi, Mayu, Sai, and baby Jyobu when the Wind Gang destroys their home. Traveling across Japan in search of their father, Tetsu journeys with the group who depend on the giant clockwork doll Homura for both protection and transportation. As a child in this ensemble, he shares the collective experiences of displacement and danger following the attack. During the journey toward Takayama, Tetsu and another younger brother receive temporary shelter from a woman dwelling in a forest house. This woman, mourning her own lost children, provides them care and refuge, revealing moments of vulnerability and temporary sanctuary for the group's youngest members. Tetsu remains consistently present within the traveling party during their encounters with historical figures and conflicts. He persists among the children relying on the group's collective resources and Homura for survival throughout their quest.