Shirokusa is Sueharu's first love—basically the girl who started it all for him. She's got that whole package going: genuinely talented as a writer (she actually won the Akutami Award, which is legit), naturally beautiful, and the kind of presence that makes her the school's go-to idol. People definitely notice her.
Visually, she stands out with her red eyes and long black hair, though the anime went with dark purple instead. She's usually seen in her school uniform with a white clover hair clip, which has become pretty iconic for her character.
As for her name, Kachi's a reference pull from Fire Emblem—specifically Catria, one of the Pegasus Knights from the series. It's the kind of detail fans appreciate if they're into that sort of thing.
Content compiled by AnimeList.moe from publicly available sources.
