In Japanese, saisen (賽銭) is money offered to the gods or bodhisattvas. Commonly this money is put in a saisen box (賽銭箱, saisen-bako), a common item at Shinto shrines and Buddhist temples in Japan.
Used to collect offerings, a saisen box is typically a wooden coin box, with a grate for the top cover. This design allows coins to be tossed in, while still preventing the money from being retrieved easily. Some have grates made of round bars, or have borders that slope downward, allowing the money to slide into the box easily.