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.
Kurumi wants to help you out
A stern face but not a stern mind
Take a relaxing bath with Clover
Kurumi showed you her admiration
Enjoy a nice summer vacation
Convince Suki to stay
Enjoy a nice dessert with Suki
Let Clover help you to relax
Suki prepared your favorite breakfast
Don't look up things in the internet
Prove that the girls are 'madly in love'
Watch the cliché happen
Tell Kurumi what's on your mind