This is the manga known as Ouran Koukou Hosuto Bo (or more commonly known as Ouran High School Host Club). The anime is about a love story, and is a comedy between the two "protagonist". It was because of the romance that I've thought of the song "Carrot and Stick", as both Tamaki and Hikaru are vying for her attention, but only one will win.
This scene in particular made me think about the relationship between Tamaki and Haruhi, and it made me think of the different ways that the relationship that she has differ from one another.
Reason: The main reason I chose this song was because the two were declaring their love for Russia, though it may not seem as though Ukraine does that. (Also taking some of this from the wiki, but that's besides the point.) The song portrays the different ways that the two show their love for him, as Tamaki and Hikaru do, and the reaction from Haruhi is different, as Russia's reaction would be if the song was ever sang to him. I see Russia freaking out about his younger sister's while being confused about Ukraine's "declaration of love". To me, this would be very similar to what happens with Tamaki and Hikaru--to me, Hikaru didn't really convey his feelings, and did it in a very similar way as Ukraine. Tamaki, on the other hand, got his feelings across, and did get Haruhi (though Russia doesn't get together with Belarus, as far as I know.)