“Otoshi is an appetizing small dish served as soon as a customer sits down in a Japanese bar or Izakaya(tavern) “at night(Quote from weblio).
During the stay in Japan, many overseas visitors must drop in Izakaya . You would get happy if you choose good Izakaya. Nice food, comfortable atmosphere, reasonable price! Some Izakaya specializes in fish, some do in Yakitori(Bite-size pieces of chicken grilled on a skewer). Walking in the busy city such as Shinjuku, we are at loss in which Izakaya to have dinner sometimes.
In Izakaya, a waiter/ess automatically serve you an hors d’oeuvre at first and you have to pay for it later, even though you did not order it. It is a fixed dish. You might get upset if you did not know this system.
It is better to consider Otoshi as a kind of table charge in Izakaya or bar. Though we usually cannot skip it, most of stand-up Izakaya and bars do not take any table charge. You might decline otoshi in some restaurants or change the menu to the other apptizer in case that you would not like a fixed one. Please check it.