Here is the full list of all 44 Mr. Massagy achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Read all the credits
Get 50 Massagys
Get a massagy with Cake-chan
Get three stars with Cake-chan
Get a massagy with a duck
Kill 100 ducks
Get a massagy with S.O.N.I.A.
Get three stars with S.O.N.I.A
Get a massagy with Navia
Get three stars with Navia
Turn volume to the max!
Take a 20 minutes Massagy
Take a 15 minutes Massagy
Take a 10 minutes Massagy
Take a 5 minutes Massagy
Take a 1 minute Massagy
Get 20 Massagys
Check your stats
Get a massagy with Sarah
Get three stars with Sarah
Get a massagy with Martha
Get three stars with Martha
Get a massagy with Papu Aiye
Get three stars with Papu Aiye
Get a massagy with Anne
Get three stars with Anne
Get two stars in a date
Get a massagy with Dorothy
Get three stars with Dorothy
Get a massagy with Mayo
Get three stars with Mayo
Tap the Mayonnaise
Get 10 Massagys
Fail a date
Get a massagy with Janein
Get three stars with Janein
Get a massagy with Nicole
Get three stars with Nicole
Reject a date on Linger!
Get a low intensity massagy
Get a high intensity massagy
Get a massagy with Rial
Get three stars with Rial
Match a date on Linger