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