Here is the full list of all 15 SUMMER VACATION achievements.
Had your first date with Alice.
Meet Alice for the first (?) time.
View the happy ending.
View the normal ending.
Study with Alice.
Smashed a watermelon with ultimate power.
Caught a lot of fish.
Earned a decent amount of points in frisbee.
Earned the max amount of points in frisbee.
Had a long rally in volleyball.
Proof that you smashed a lot of bottles.
You're a failure of a boyfriend who ruined every date.
You made every date a joy, proving yourself the perfect boyfriend!
Completed the tutorial.
Caught every type of fish.