godan verb (-ru), intransitive verb
accumulate; be saved up
Used for money, points, or other countable resources that build up over time. Intransitive; the thing that accumulates is the subject.
毎月少しずつお金が貯まってきた。
Money has been gradually accumulating each month.
ポイントが貯まったら景品と交
When you accumulate points, you can exchange them for a prize.