Momoko is a character created specifically for the 1990 anime adaptation of Mōretsu Atarō, the second television series produced by Toei Animation. She does not appear in the original manga or in the earlier 1969 anime. Her visual design was based on Totoko from Osomatsu-kun, but she was drawn with a shorter stature similar to the main characters Ataro and Dekoppachi. Momoko is introduced as Ataro's childhood friend and his primary love interest, serving as an additional female character to support the cast. She is described as very sweet and well-mannered. In the story, she takes on the role of a fixed girlfriend figure for Ataro, a notable addition that was not present in the original source material. Her relationship with Ataro is the central personal connection she has within the series, and through her interactions with him and the other characters, she contributes to the everyday neighborhood atmosphere of the show. No information is available in the provided context regarding her personal background, deeper motivations, character development over the course of the series, or any special abilities she may possess.