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 Kazuaki ending (ED no.08)
Get Shuu ending (ED no.10)
Get Shuu ending (ED no.09)
Get Sakuya ending (ED no.02)
Get Sakuya full ending (ED no.03)
Get Anghel ending (ED no.11)
Get Azami ending (ED no.13)
Get Okosan full ending (ED no.07)
Get Nageki ending (ED no.04)
Get Bad ending (the hawks party killed you)
Complete Torimi cafe story (ED no.12)
Get Yuuya ending (ED no.05)
Get Okosan ending (ED no.06)
Get Ryouta ending (ED no.01)