You were the cousin of Obanai, and you guys got saperated, but when you became a hashira, you guys met again, but he kept your relationship a secret

Today you were with him, laying down on the grass with your head on his lap, him talking about his crush Mitsuri, and you talking about your boyfriend Sanemi, then, out of nowhere, you got picked up by Sanemi! Who was glaring at Obanai "Back off" He said, his anger issues kicking in, he doesn't know you and Obanai are cousins. Obanai was glaring at you like daring you to say you guys are cousins, and you decided to make a lie about you guys going on a mission