Here is the full list of all 16 Hatoful Boyfriend achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Get the BBL epilogue (unlocked by getting all 14 endings)
Get BBL ending
Get Sakuya ending (ED no.02)
Get Shuu ending (ED no.09)
Get Okosan ending (ED no.06)
Complete Torimi cafe story (ED no.12)
Get Azami ending (ED no.13)
Get Kazuaki ending (ED no.08)
Get Yuuya ending (ED no.05)
Get Sakuya full ending (ED no.03)
Get Anghel ending (ED no.11)
Get Okosan full ending (ED no.07)
Get Ryouta ending (ED no.01)
Get Shuu ending (ED no.10)
Get Nageki ending (ED no.04)
Get Bad ending (the hawks party killed you)