Natsumi Kawashima, an energetic fifth-grader, is obsessed with her fantasy of being the ideal, sexy woman. Rejected at every advance for the cute guys that she fawns over, she's finally given a lucky break when she picks up a package of mysterious pink nuts that are "only for adults". These nuts cause her to morph into a sexy adult, and things seem to be going her way when she's offered modeling opportunities at the hands of men. However, things don't work out as well as she'd planned, because she knows she's still a child on the inside and has plenty of lessons to learn

Natsumi Kawashima
An energetic fifth-grader who wants to be as beautiful and sexy as the models she sees in magazines. Fawning after cute men who are way out of her league, Natsumi goes to comical lengths to appear older. She is bothered immensely by her obnoxious next door neighbor, Asuma, but also finds him to be the only one she can confide in.

Asuma Yoneyama
Natsumi's best childhood friend and next-door-neighbor. He's got a big mouth and never hesitates to tease her. On the inside, however, he's a soft-hearted boy who cares greatly for Natsumi, and shows a lot of guts by confessing his feelings for her. He often accompanies Natsumi on their wild adventures, ready to console her and lend a listening ear.

Prof. Hakase Morinomiya
A 'mad-scientist' who created the mysterious pink beans that make things grow at an accelerated rate. He is a light-hearted, goofy guy who prefers to stay out of Natsumi's and Asuma's affairs, though he's always willing to go with them on their travels.

Haruka Fukushima
Date of Birth: April 12, Aries, Blood-type A, raised in Okayama Prefecture (in the Chuugoku area).

First appeared in the 28th issue of Nakayoshi Magazine in 1999, with her award-winning manga, Cherry Kiss. She considers Otona ni Nuts to be her masterpiece.

Her hobbies include walking her dog, jogging and do-it-yourself carpentry. Climbing trees is her specialty and her favorite food is omusubi (rice balls.)