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