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