The otoshi is a firmly rooted izakaya tradition in Japan, going back generations. While many would rather it didn’t exist at all, it's often used in place of a seating charge, presumably ensuring that even customers who nurse their drinks and get lost in conversation still pay enough to warrant taking up a table. For this reason, it's customary for izakaya staff to introduce the food as otoshi when placing it on the table as a way of avoid situations where customer demands that it be removed from their bill on account of not having ordered it.

Looking at the kanji character used in the word, otoshi can be thought of as literally meaning “passing through” (通る toru), or to make a path between two places (通す tosu). This lends weight to notion that the miniature dish was originally intended as something to occupy the customer and keep their hunger at bay between the time they place their order and when their food arrives. Another theory regarding the origin of the word is that, after the waiter or waitress had taken an order, they would return with these small dishes, taken from the kitchen, almost as proof that the order had been properly relayed. Unlike in the west where people often go to pubs and bars with the sole intention of drinking, it’s still typical in Japan for alcohol to be consumed alongside food, which, when you think about it, probably isn’t the worst idea.

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