Naotsugu Miura is the eldest son of the Miura family and a regular customer at the Kihei Restaurant. His real birth name is Airmori, a detail revealed later in the story. He becomes deeply troubled when he notices that the people around him seem to have forgotten about his older brother, whose mysterious disappearance haunts him. Seeking answers, he asks Jinta to investigate the truth behind his brother's absence. Naotsugu serves as both a samurai and a civil administrator for the shogunate, and he is introduced as a supporting character in the Edo period. He is known for his unusual warmth and genuine decency toward people of all social classes, which sets him apart from many of his peers. Beneath his approachable exterior lies a strong fixation on swords, a passion that is directly tied to his search for his lost brother and his desire to understand his family's severed history. His primary motivation is to reconnect with his brother and uncover what happened to him, but he also carries a strong sense of duty to protect the people around him. Naotsugu becomes one of Jinta's most steadfast allies, and he fights as a noble warrior to keep others safe. He eventually marries Kinu, formerly known as the Harlot, a relationship that demonstrates his willingness to reject social prejudice. Over the course of the story, he takes the side of the Emperor during the Boshin War, showing his growth into a committed figure in the larger conflict. In terms of abilities, he is highly skilled with a sword and is both a capable warrior and an effective administrator, using his talents to uphold justice and aid his allies.