Hayate no Gotoku!!

Synopsis

The day before Valentine's Day, Nagi tries to make chocolate for Hayate and skips school. At Hakuou, getting permission from Hinagiku, Ayumu tries to give Hayate "love chocolate" to show her feelings but instead gives him obligation chocolate. Hinagiku notice Ayumu panicked and tells Hayate to exchange it. However, after receiving the "love chocolate", Hayate is a bit confused on the love concept and asks Maria for help. Maria remembers that she has had no experience with love either and becomes dejected. However, she decides to make some chocolate for Hayate. Nagi, after failing herself to make chocolate, tells Hayate to make some chocolate for her. Maria makes her chocolate look outrageous, but when asked about who it is for, she becomes embarrassed and runs outside. Hayate catches up to her and gives her some chocolate that he made, and says Valentine's is the time where people work harder just to see the person they treasure smile. Ayumu thanks Hinagiku for helping her; leading Hinagiku to think that Ayumu and Hayate are a couple now.

(Source: Wikipedia)