Hiromi Matsuno

Hiromi is a woman who earns her living as a professional animator, working among a studio's drawing staff.

Talented yet deeply insecure, Hiromi keeps measuring herself against her colleague Kazuko and concluding she falls short. That gnawing doubt drives her to break a shared promise in secret, convinced it is the only way to keep pace. Once she is freed from the influence pushing her, she owns up honestly and rediscovers the earnest passion for animation that first bonded the two of them.

Hiromi partners with Kazuko Tadashita on a Sailor V cartoon. Early in their friendship the pair had bought a set of special pencils and sworn not to touch them until each had become a true professional, and even then only with the other's blessing. As the work drags on, Hiromi loses confidence in her ability, certain her output cannot match Kazuko's, and quietly opens her pencil case without permission, treating the tools as her only means of keeping up.

Nephrite singles her out and plants the Youma Castor and Pollux inside the last pencil she has left. Under that dark sway she turns cold, quarrels with Kazuko, and insists that Sailor V should be killed off at the finale of the cartoon they are producing, appalling Kazuko, the director, and the rest of the crew. After the Sailor Senshi free her from Castor and Pollux, Hiromi confesses to using the pencils, only for Kazuko to admit she had felt exactly the same way. The two renew their shared dream of making animation together and seal the reconciliation with a pinky promise, all of it witnessed by the guardians.