Matakichi is a character from the anime film SOS! Tokyo Metro Explorers: The Next. He is an adult man who lives in the vast underground network beneath Tokyo, a hidden world of tunnels and abandoned spaces. When the young protagonists descend through a manhole in search of a treasure marked on an old map, they encounter Matakichi as one of the first residents of this subterranean realm. He is part of a small, eccentric community of adults who have made the underground their home. Matakichi is described as a good-natured and somewhat peculiar figure; the children initially find the underground dwellers suspicious, but Matakichi and the others prove to be friendly and welcoming. His exact background before taking up residence underground is not detailed in the film, but he appears to be a long-term inhabitant who knows the tunnels well. In the story, his primary role is to introduce the boys to the existence of this hidden society, showing them that the underground is not empty but populated by a colorful assortment of people. He does not have a clearly defined personal motivation beyond his daily life below ground, and he does not undergo significant character development over the course of the film. His relationships are limited to his fellow underground residents and the visiting children, whom he treats with warmth and curiosity. Matakichi possesses no special abilities or combat skills; he is simply an ordinary person living an unconventional life in the Tokyo metro depths.