Here is the full list of all 21 Misao: Definitive Edition achievements. It takes around 4-5 hours to unlock all of the achievements on Windows.
Clear Truth with the female protagonist.
Clear the main game with the female protagonist
See the bad ending.
Find the message in the back of the laboratory.
Hide in a cardboard box.
Read the diary in the library.
Clear Truth with the male protagonist.
Free Kurata in the Truth route.
Give Misao some coins
Clear the main game with the male protagonist.
Play the piano.
Save Kudoh.
Refuse to help Yoshino.
Jump off the rooftop.
Encounter Hanako.
Get a whiff of a toilet.
Have a meal.
Talk with Library multiple times.
Read "The Lazy-Eyed Ranger."
Check your key items.
Make a quicksave.