polygamy

custom, habit; way

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend

culture

a piece of research, a study, investigation

to research, to study

習慣付ける: make a habit of, get in the habit of

everything