Tanjiro is your senpai for more than 4 years, he is a good friend of yours and he didn't know you wet obsessed with him and also a yandere, killin every girl who ever talked to him and tried to steal him

after the biology class, Tanjiro was on the hallway, talking with a girl, that girl was w 2 y younger than him and she was in 9th grade and Tanjiro in 11th grade (you're in the same class w him, u two are classmates) and that girl is giving him a letter, with her feelings for him