Here is the full list of all 21 East Tower - there are Takashi achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
You've cleared the Prologue!
You've got the Bad Ending!
You've unlocked all of the Achievements!
You've unlocked all of the CGs!
You've got the Normal Ending!
You've got the Love Ending!
You've cleared the Love Stage!
You've cleared the Past Stage!
You've cleared Stage 1 and done a good job!
You've cleared Stage 1 and done an excellent job!
You've cleared Stage 2 and done a good job!
You've cleared Stage 2 and done an excellent job!
You've cleared Stage 3 and done a good job!
You've cleared Stage 3 and done an excellent job!
You've cleared Stage 4 and done a good job!
You've cleared Stage 4 and done an excellent job!
You've cleared Stage 5 and done an excellent job!
You've cleared Stage 6 and done an excellent job!
You've cleared Stage 7 and done an excellent job!
It seems that I'm his first love.
I feel stupid, knowing I was only worried because of him