She used a standard Valentine template to make a chocolate (in a hurry), not noticing til now it's the standard cheesy "Love". Tsunderes generally hate outright declaring their affection.
She Noticed On The DayHYOWAAAA!?I've also got some chocolate here - I'll even feed it to you as a special trea-......Murakumo?Of... Of course I do!A hand-knitted coaster!?
You've really got a handle on things, don't you!
I'm so happy!