Here is the full list of all 13 Sakura Gamer 2 achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
A stern face but not a stern mind
Kurumi showed you her admiration
Enjoy a nice summer vacation
Enjoy a nice dessert with Suki
Kurumi wants to help you out
Convince Suki to stay
Tell Kurumi what's on your mind
Watch the cliché happen
Prove that the girls are 'madly in love'
Take a relaxing bath with Clover
Don't look up things in the internet
Suki prepared your favorite breakfast
Let Clover help you to relax