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