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