One of Ichijou's younger sisters, Ayumi is just as mysterious. She is the third sibling in the Ichijou family who appears to be too young to converse so she relies on drawing on a sketchpad to communicate. She is the only other person aside from Ichijou who is aware of the aliens keeping watch over Becky.

In episode 7, she has a large role when she comes to school and causes some trouble. She appears regularly after this, including episode 15 and is the bringer of the disease from the alien spaceship which affects the class in episode 19.