Ushio Kazama

Ushio is the best friend of Sumika, the protagonist, and always has been —oblivious to Sumika's feelings for her (though she does at one point recognize that Sumika is in love, and feels guilty, even, for not realizing it sooner; she just doesn't understand that it's her Sumika feels that way with). Ushio has made it clear that Sumika isn't her type; Ushio's "type" consists of —cute— girl; small and feminine and innocently curious, the kind one would want to protect, and Sumika far from falls into that category. (Source: MyAnimeList)