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 male protagonist.
Give Misao some coins
Clear the main game with the male protagonist.
Find the message in the back of the laboratory.
Clear Truth with the female protagonist.
Free Kurata in the Truth route.
Clear the main game with the female protagonist
See the bad ending.
Play the piano.
Hide in a cardboard box.
Refuse to help Yoshino.
Save Kudoh.
Encounter Hanako.
Jump off the rooftop.
Have a meal.
Get a whiff of a toilet.
Talk with Library multiple times.
Read "The Lazy-Eyed Ranger."
Read the diary in the library.
Check your key items.
Make a quicksave.