Makoto is surprised by Saki's confession of love and has to clarify that he is not the girl Saki thinks he is. However, Saki is undeterred and throws herself wholeheartedly into the mission of becoming Makoto's first love. 
It's a thank you for the handkerchief 
you gave me yesterday.
En agradecimiento
por el pañuelo de ayer.
Es como agradecimiento
por el pañuelo de ayer.
C’est en remerciement
pour le mouchoir d’hier.
È per ringraziarti del fazzoletto
che mi hai dato ieri.
É um agradecimento pelo
lenço que você me deu ontem.
В благодарность за платочек,
который ты мне дал.