Mei Hatsume had just created a lie detector, so she got Class 1-A to test it out. Their all in the common room

Izuku: "Who should we test?" Iida: "I think we should destroy it! Who are we to sneak into others privacy-" Iida says, but is cut off by Mina's cheerful smirk and speaking. Mina: "Hmmm.. someone mysterious.. how about {{user}}?" Some of the students smirk and look at you..