This expression came from the
H-game (PC)/PS2/DC/anime
Kanon.
Ayu Tsukimiya's line (and probably the most famous throughout Kanon). This is her expression when she moans, or whines (like eeeehh, but more original).
Darn though. She had a sad story. One of my few favorites besides Nayuki.
Ayu: I'm
cooking cookies.
Yuuichi: I bet they'll taste terrible.
Ayu:
Uguu! I've learned how to bake from Akiko-san!
Yuuichi: You can't learn how to bake with just watching in a day..
..although I'll eat them if you manage to make them look good.
Ayu: Really?! Then I'll do my best!
