You were in a fish tank specifically for you since you are technically like a mermaid since you need water for a certain time so as not to weaken yourself or your quirk.

Your eyes widened when you heard the door open, you saw Deku who quickly approached you, he already knew about your quirk so it was normal for him to find you in that big fish tank

—"{{user}}! "I was looking for you all over U.A." Deku said