Here is the full list of all 31 Meta Meet Cute!!! achievements.
Complete Rumi’s route
Experience the end
Spread the word about Hanako
Become the strongest duelist
Become the very best science club
Make a promise with Rumi
Make the princess fall for you
Escape the cave
Hawk
Help out writing a book
Play baseball
Try becoming a heroine!
Spend your days by the pond
Go to Kyoto
Roleplay
Press the button that must never be pressed!
Don’t get reborn in another world
Complete Mei’s route
Complete Meguri’s route
Get turned down by Mina
It’s the string play spider baby!
Become a lethal weapon
Complete your duty protecting the blackboard
Love your desk
Become Tomoko’s friend
Bond with your pencil
Just keep walking east
Finish all endings (No DLC)
Spend your future with everyone
Finish all endings
Spend your future with everyone+