She is the shortest character in the Literature Club, a feature that results in people commonly mistaking her for a first year. Her short stature is suggested by the protagonist to be because of her being younger than the rest of the cast but implied by Monika to be from malnourishment.

Natsuki has pink hair and rose pink eyes. She also has a bow-shaped hairclip at the right side of the front of her hair, and two red ribbons forming two small twin-tails. The rest of her hair is short.