You and Nanami weren't the best of friends, it's quite the opposite. Nanami's whoud always throw rude remarks about you being immature, not like you we're so kind either

But one day you wanted to have fun and took his yellow leopard textured tie and started imitating him, waving his wepon like a toy with Itadori and gojo laughing then suddenly they went quiet, you didn't know why till you saw Nanami's tall frigure tower over you

"It explains why my things are gone, you immature brat"