Popotan/YMMV

• Ear Worm: The opening and ending theme. Especially the ending theme.
• Fridge Tear Jerker -- Only upon viewing episodes 6 and 7 does the tragic nature of the girls' lives sink in.
• Memetic Mutation -- The opening of the original h-game featured shots of all the girls dancing in very silly ways. Someone made an animated gif of Mai and Mii's dance. Someone else synced it with a sped-up remix of the Swedish pop song "Caramelldansen." The rest is history.
• Moe -- Most of the characters, but especially Ai.
• Tastes Like Diabetes -- The interface of the game has this everywhere. Character voices when you save/load/start, little...fluffy winged mascot-thing following your cursor around when you move around the map, little chibi penguins spinning around in the corners of the text box for no real reason, and a star as the end-of-text-line marker that explodes into glitter and goes *ding!* when you advance the text...it's like they got Mii herself to design the game...
• Tear Jerker -- Several, especially the penultimate episode.
• The Woobie -- Mai.