to stay up all night, to burn the midnight oil

being awake all night / vigil, wake

Alternative form of 勉強

to study / to discount, to reduce the price of something

studying, studies, study

examination, exam, test / quiz

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

after an all nighter