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