(figuratively) vulgar, tasteless behaviors that spoil elegant or beautiful things

koto: a Japanese zither derived from the Chinese guzheng / (colloquial) guzheng: a Chinese zither on which the koto was based

(chiefly literary) truly; indeed; without doubt

burn

action; behavior

to act

to boil, to cook

to simmer, to braise, to boil

to cook; to boil / to anger; to enrage; see 業を煮やす

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