早坂 羽未

- The Fussy Younger Sister

Just like her older brother, she’ll be attending the St. Francesca academy starting this spring with their childhood friend Yuika who's already a student of this academy since her first year.
Unlike her brother, she’s very serious when it comes to studies and lifestyle choices, but the two of them still get along great when going shopping and stuff like that.
Used to be sensitive and obedient when she was younger, but is starting to get more complex now that she’s older. She’s quite girlish, but she also has a strange love for B-grade horror flicks.

She is very friendly with her classmate Sonya, they are already inseparable.

Despite her small size and young age, she is exceptionally brave and courageous. Umi has only one fear: that Akihito no longer considers her as his little sister if he remembers the truth about who she really is. 

Contrary to what Umi reveals, she remains a very intelligent and smart girl. She, for example, quickly realized that Yuika was only "pretending" to have no romantic feelings for Akihito./