Japanese phrase
約束は守るものだよ。 yaku soku wa mamo ru mo no da yo
Meaning
A promise is meant to be kept.
When to use it
States that keeping a promise is important.
Example dialogue
明日の約束、忘れないでね。 asu no yaku soku wasu re na i de ne
Do not forget our plans for tomorrow.
わかってる。約束は守るものだよ。 wa ka tte ru yaku soku wa mamo ru mo no da yo
I know. A promise is meant to be kept.