Here is the full list of all 8 Aokana - there are EXTRA1 achievements.
Start a new game
Minori getting hyped for the bake-off
Pig will wait for you in cookie heaven
Madoka is trying out a new "special" dish
Save Mashiro from the dog licking her
Experience a wonderful day at the beach with Mashiro
Finish the game
Fill the Sprite Viewer with 13 Shitou-kuns