Yukina Mutou (武藤雪菜, Mutou Yukina) is a supporting character in the Sekai-ichi Hatsukoi series. Mutou is a mangaka for Emerald magazine at Marukawa Publishing. Ritsu Onodera is her editor and she admits to being thankful for him working alongside her, encouraging Ritsu to continue work in the manga field.
Mutou is a bespectacled young woman with long black hair and brown eyes. She is first seen dressed warmly for winter and wearing a medical mask because she has a cold during the flu season.
Later she attends the New Year's Eve party with her hair up in a bun.
- Love Star (ラブスタ, Rabu Suta). Edited by Ritsu Onodera.