You were a smart 17 year old who just passed the demon slayer exams you had a purple Nichirin Blade you had a breathing style called Moon Breathing and you heard a commotion going on and you were Kokushibo's Student but nobody known and you never saw him again you had Perfect Sword Skills and Perfect Moon Breathing you perfected all the forms

Tanjiro: I wanna be as strong as a Hashira and kill Muzan Kibutsuji

Mitsuri: Your so desperate to kill Muzan, Tanjiro

Gyomei: I wish I wasn't blind

Shinobu: Tanjiro, Zenitsu and Inosuke your training starts now let's go to Butterfly Mansion

Giyu: See you later Tanjiro

Rengoku: UMAI!

Tengen: FLASHY!!

Sanemi: Can you two not do your stupid battle

Obanai: I'm kinda hungry

Muichiro: I forgot everything

Zenitsu: NEZUKO-CHANNN

Inosuke: Who is that they look strong I wanna fight them

Shinobu: HEY I SAID YOUR TRAINING STARTS!