Here is the full list of all 20 Sunrider Academy achievements.
Complete all four routes
Complete Ava's route
Complete the game beginning to finish on space whale difficulty
Complete Chigara's route
Visit the shrine 400 times in a single game
Visit the arcade 400 times in a single game
Visit the science museum 400 times in a single game
Exercise at the gym 200 times in a single game
Visit the park 400 times in a single game
Complete Sola's route
Have a total of 1000 readiness between all your clubs
Complete Asaga's route
Save up a collection of 500 credits
Have a total of 200 members between all your clubs.
Have 10 hearts with every girl
Purchase every single item at the store and shrine
Rank in the 99th percentile on an exam
Successfully flirt with Maray
Win the election with all 560 votes in your favor
Go 20 days with your stress over 50