Here is the full list of all 15 Sakura Forest Girls achievements.
Mika has an offer
No beauty sleep needed
It's just a dream
Help your clumsy friend
She is supposed to be a witch?
Not as light as she looks
Those were not the proper sounds!
Let the thoughts run over you
The stars contian so many stories
Syncing mana levels
Get ready for the ritual
More than childhoof friends
Get Maia's Ending
Achieve the Harem Ending
Whatever comes, you can do it together