To do what one has promised.
約束したことをする。 (yakusoku shita koto o suru)
"She was true to her word and helped me finish the project."
"彼女は約束を守り、私がプロジェクトを終わらせるのを手伝ってくれました。" (kanojo wa yakusoku o mamori, watashi ga purojekuto o owaraseru no o tetsudatte kuremashita)
an exact or equivalent match in value or amount
born into a wealthy or royal family
to work too hard without enough rest
to trust that someone is telling the truth
to be very close friends
someone very precious or loved
