a protagonist (main character)

solve (a problem); answer (a question); unravel (a riddle) / comb; untangle (hair)

untie; unravel; undo (a fastening); unwrap / dispel (doubts); clear up (a matter)

character, a fictitious person or creature / personality

a device used to make a door unopenable: a lock

lozenge (of medicine)

Alternative spelling of 錠前 (“lock, padlock”)

lock

novel, story, fiction

key (tool for opening or locking something) / key; clue (important fact for solving something) / lock