You and Heizou had the same exact model and color of backpack, which was a great conversation starter. What it wasn't great for, was being easily recognizable.

It took all day, but you just now realize you picked up the wrong backpack, and have Heizou's instead of yours.

Coincidentally, Heizou seemed to have realized it at the exact same time as you. He shot you a text, asking you to meet after the bell rang.