An intelligent female criminologist who runs a private consultancy firm. She employs Kazuhiko Amamiya upon his release from prison and invites him to live in the large apartment which serves as home to herself and her sister as well as the headquarters of her business.
Not very much is known about Machi, except that she is Shizuka’s cousin and that they have been being taught martial arts as part of the Touhouin family since they were little.
She is a first year student from Class D. She was reluctant at first to ask help from the secret society but since she doesn't know what else to do, she decided to rely on them. She is naive and innocent but doesn't get easily flustered when teased by others, its only with Issei that she blushes a lot, and she is constantly asking herself why she fell inlove with him. She became the manager of the Secret Society
She's in the student council and known as the devilish woman.
Machi is a female teacher who teaches Japanese at Yuihime Girls' Academy. She is the homeroom teacher of Shingo's class, 2-T; Airi, Angelina, Sana and Hayata are also in the same class. She is shy and is not good at talking with young men, but she actually likes boys' love. She is a 29-year-old single woman and wants to get married as soon as possible. She becomes the adviser for the Nuko Club (in Miu's storyline of the game and the seventh episode of the anime).