Here is the full list of all 20 the 9th day achievements.
accomplish all above and get a platinum trophy.
Game time breaks through 20 hours.
Occupy all archive places.
Through the link in game to arrive at the official shop.
Through the link in game to arrive at the official blog.
Through the link in game to arrive at the official website.
Another story pass.
Go through the whole game following the option order.
Collect all CG.
Saki line pass.
Pass Saki line again after passing Another story.
Suzu line pass.
Mai line pass.
Maki line pass.
Appreciation mode all music listen once.
Watch ED for the first time.
Watch OP for the first time.
Prologue finish.
Game time breaks through 10 hours.
Save the game once.