Mutō is the central character of the anime That is the Bottleneck, a convenience store employee at the Hot Hot Mart. His background is shrouded in mystery; he is a model worker who is considerate and diligent, yet his face is perpetually concealed, and he is followed by an ominous cat named Nekomaru. His personality appears helpful and efficient on the surface, but the reactions of those who catch a glimpse of his hidden face suggest a darker, more threatening presence. Mutō’s motivations are ambiguous—he seems to seek connection with others despite his inability to show his true face, and the series uses his character to explore themes of communication in modern society. As the protagonist, he is the central mystery around which the story revolves; each episode focuses on a different coworker or customer and their personal bottleneck, gradually revealing clues about Mutō’s nature. He interacts with a cast of coworkers including Otsuka, Oda, the store manager, Tabata, Adam, Ueno, and Tsukiko, with the cat Nekomaru appearing as a constant companion. Development occurs slowly through hints and unsettling incidents; the final episode strongly implies that Mutō may have killed Otsuka and used his flesh to fill onigiri, suggesting a horrific, possibly supernatural side. Notable abilities include working effectively despite his hidden face and an implied capacity to exist without a visible head, as well as the power to instill fear in those who see his true appearance. His ultimate identity and intentions remain unresolved, leaving him as an enigmatic figure.