@MrOGZ That text box at the bottom right on the last page means "A taste that got the little sister nervous" or alternatively(and more directly) "A taste that got the little sister's attention". It also has a マネ(mane) ending/suffix, which I'm not familiar with, but it might just be a idiosyncratic ending peculiar to this manga. I haven't read it in Japanese that much.
Also, the text box on the lower left on the last panel on the last page says "And thus Takeda-kun got thoroughly interrogated by Yuki-chan later". There's nothing about him eating the chocolate meant for Yuki, the implication is that Yuki got jealous after he passed Takizawa's handmade chocolates to her.