Marimo is a minor character who appears in the eighth and twelfth episodes. She is a former Fuhshin Gazette employee before she graduated from college, and has a reputation as the worst employee the newspaper company ever had. Nevertheless, she was well liked by everyone. She and Saki shared a special friendship; they were so close that Saki started calling her nee-san (big sister), which the rest of the Fuhshin staff picked up, as well. Marimo was the first person with whom Saki had truly opened up and revealed her true feelings (and as far as the series has shown, the only person). She is also the only staff member, overall, to call Saki by her name, instead of addressing her as chief.

Before the events of the anime (roughly the most recent spring season), the day before Marimo's graduation, there was a snow storm with record low temperatures, and on that day Marimo was late returning home. Hinata offered to look for her, and recruited the others to do the same (although tactfully omitting Haruka from the search). She found Marimo's bike crashed by the river, with stacks of newspaper rolls leading to the water's edge. Saki, upon hearing this, ran into the storm to search for her, eventually getting herself lost. Marimo then finds Saki at the place where the bike crash was, where it was revealed that Marimo was merely searching for a lost kitten. Saki berates her for making her worry, and they share an embrace.

Currently in the story, she lives off of odd jobs, such as selling vegetables in the flea market for outrageously cheap prices. When she is not working, she will, according to her words, "go where the wind takes her, where her mood takes her". She also meets Kana in episode 12, although she was never recognized by Kana, at least by her name.