Here is the full list of all 27 How to Sing to Open Your Heart achievements.
You've cleared the Prologue!
You've cleared Bonus★Independent 1!
You've cleared Bonus★Teamwork 1!
You've cleared Bonus★Independent 2!
You've cleared Bonus★Teamwork 2!
You've cleared Bonus★Independent 3!
You've cleared Bonus★Teamwork 3!
You've cleared Chapter 1!
You've cleared Chapter 2!
You've cleared Chapter 3!
You've cleared Chapter 4★Independent!
You've cleared Chapter 5★Independent!
You've cleared Chapter 6★Independent!
You've cleared Chapter 7★Independent!
You've cleared Chapter 8★Independent!
You've got the Independent Route Ending!
You've got the Teamwork Route Ending!
You've cleared Chapter 4★Teamwork!
You've cleared Chapter 5★Teamwork!
You've cleared Chapter 6★Teamwork!
You've cleared Chapter 7★Teamwork!
You've cleared Chapter 8★Teamwork!
You've unlocked all of the Achievements!
You've unlocked all of the CGs.
You've unlocked all of the Music tracks.
We don't need words to express this feeling.
Nothing can suppress this feeling anymore.