Mika is one of the characters of the day that appear in "Doremi's boyfriend is a junior high student?!".
Mika has dark blue eyes and shoulder-length hair. Her bangs are brushed to the left of her head to frame it. She wears a white top beneath a dark pink tank-top with an olive-green design on the chest, along with dark pink shorts, purple fingerless gloves, and pads on her elbows and knees, and a white, pink, and purple helmet to match her skates.
Due to being a one-shot character, not very much is known about Mika. From what can be told, however, she is very tomboyish and has a cool, neutral type of vibe in which she does not show very much emotion, even when confronted about it. She keeps quiet about how she really feels and acts somewhat like a tsundere when in romantic situations.
She may be seen as an older sister/motherly figure to Shuzou's younger sister and classmate of Doremi's, Maki Higuchi.
After formally meeting Doremi she soon grew jealous over her relationship with Shuzou and began to act coldly while he tried to figure out what was wrong. After the girls realized Shuzou actually didn't like Doremi, they attempted to get the duo to reconcile. Mika wanted nothing to do with Shuzou at first and assumed he faked the entire event- but in the process of storming off, she nearly got hurt. Shuzou protected her, resulted in them both being slightly injured, but not seriously hurt. In this time they confessed their feelings for one another.