She is one of the first Taimanin that Fuuma Kotaro captures in Taimanin Asagi Battle Arena, and becomes involved in the main quests, as well as appearing as a side character in some event quests. Momoko is a naive, slightly dim and nervous girl. She is usually serious and patient, but struggles to speak up for herself, so she often winds up with other people's chores foisted upon her. Deep down, she's frightened of fighting; and in one timeline, she expresses a deep sense of relief when she is offered an opportunity to live a normal life raising a big family, rather than keeping up the front of strength required by the Taimanin lifestyle, and deal with its dangers.

She drinks milk every night because she is worried about her height. Momoko says that tricks and deception will not fool her, and she is known for her high moral principles.

She is very interested in dating and reads romance comics. Furthermore, believes strongly in love at first sight. While, she often is holding weapons battle ready, these are only used to scare people and help her Ninja Art. Momoko is a Taimanin in training, working for Gosha Village.

She is a second-year student on the Discipline Committee of Gosha Academy. She became proficient in ninjutsu in her first year, and has experienced several actual battles. Born into a family of genuine Taimanin, she believes that her role is to avenge evil, but she is afraid to fight. She is currently solely focused on improving school morals, and stands at the school gate every morning to check for tardiness and to call out to the students.

Not the strongest Taimanin and her ability works more subtle than directly for fighting. She has an older sister, which is an on duty Taimanin and Momoko wishes to get closer to her. While still in training, in the year 2082, Momoko was sent on an unspecified mission to Tokyo Kingdom City. One of Fuuma Kotaro's sources drew his attention to her for her potential and lack of experience, and Kotaro decided to make Momoko his first 'recruit' for the Fuuma