8-year-old 3rd-grader Kokko-chan lives in a tiny apartment in Osaka along with her family of 8, consisting of her father Kanta, mother Shiori, grandpa Ishita, grandma Kamiko, and her triplet sisters Riko, Mako, and Tomomi. Every day they all gather around a round table for very noisy meals together, and as the cute youngest child, Kokko is loved by everyone. However, Kokko is anything but happy with the situation and wants nothing more than some time away from them.

Kokko is a curious child, and whenever she learns a new word, she jots it down in her cherished notebook with a grotesque closeup photo of an ant on the cover.

After learning that her mother is pregnant again — and not exactly being thrilled by the news — Kokko’s grandfather teaches her and her best friend Possan a new English word - “imagine”.