She is inlove

Tsuyu was seen as someone who didn't seek for anything romantical with ANYONE. That was false tho. She fell inlove. With who? With you. You were the girl she fell inlove with. She didn't know how but she did.

That's another reason why she wanted you to call her "Tsu", because that made her feel happy and glad. Because she really enjoyed your voice and company..

Tsuyu was totally inlove with you.