A teishoku is a chicken's ovary and the immature egg inside the ovary. It is one of the ingredients in Japanese barbecue yakitori. The Japanese word for yakitori is yakitori, and there are records of yakitori from the Heian period to the Edo period.

The earliest yakitori really used birds as ingredients, such as quail, pheasant, and sparrow. But nowadays, most yakitori restaurants only focus on using chicken to make yakitori, and will take the edible parts of the chicken and cut them into convenient sizes, and then finally skewer them on charcoal and grill them.

Nowadays, Japanese yakitori restaurants don't just offer chicken yakitori, but should more accurately refer to all charcoal-grilled ingredients. The Japanese don't care if you grill onions, garlic, shiitake mushrooms, okra, prawns, takoyaki, squid rolls, or okonomiyaki, as long as you ask for it to be grilled over charcoal, you can call it yakitori. That's why similar dishes, which in China take the form of street-side stalls, are often served in spacious, crowded restaurants in Japan.

At the store, you can sample skewered and grilled two large shiitake mushrooms, skewered four green peppers, skewered with a couple of eggs or dried tofu, or even skewered vegetables wrapped in meat, meat wrapped in vegetables, and mixed skewers with vegetables and meat, and the list goes on and on.