내가 누구게

Unlocked at TL22.

A common expression used when someone wants another person to try and identify or guess their identity. It's used in games, when surprising someone, or in playful interactions. Asta's companion mission is titled "You Already Know Me," which is also the alias of a researcher in the Madam Herta's Heritor Club group chat. If both are combined, one has "Guess who I am. You already know me," which implies that we are to guess Asta.