After setting up his truck, Okuno treated us to his tasty yakiimo. With the first bite, the juicy Japanese sweet potato filled my mouth and nostrils with a savory sweet aroma and left my taste buds wanting more.

Being skilled in the IT field, he gets most of his customers through social networking sites such as twitter and even has his own website. He even takes requests online for locations where customers want him to visit.

According to Okuno, it’s quite common for customers to buy not just one, but four or more potatoes at a time which really helps his sales.

So how did Okuno begin selling yakiimo on the streets and what’s his secret to creating such a delicious treat? Okuno had always been interested in yakiimo and he and his wife had been wanting to start their own business for a while.

After doing some research and looking into the cost of buying a truck, he was surprised to find a good truck that was actually quite affordable. Furthermore, the sweet potato farmer was coincidentally just right in front of that shop! According to Okuno, things just went so smoothly for him, he couldn’t afford not to start this business!

Okuno uses beni haruka sweet potatoes from the brand Inoue Satsuma. Inoue Satsuma sweet potatoes are farmed in Chikusei, a city in Ibaraki Prefecture (about two hours north of Tokyo) that was a castle town back in the day. Apparently, they used to pay taxes in sweet potatoes in the past and, consequently, the area is well known for producing some pretty tasty sweet potatoes.

Okuno sells his yakiimo at the standard prices of 400 yen for a medium-sized potato and 500 yen for large. However, in reality, the potatoes that he uses are much larger than that of other trucks. Upon examining the cases, you can see that he is actually baking and selling XL and XXL-sized potatoes and he is very particular about which ones he uses for his yakiimo.

When asked about how to make the tastiest yakiimo, Okuno told us that that temperature control and how long you bake them greatly affect the quality of the product. He first wraps the sweet potatoes in aluminum foil and puts them in the gas-powered oven grill in the back of his truck.

He uses a thermometer to watch the temperature of the potatoes. According to Okuno, the ideal temperature for the inside of the potatoes is 70-80 degrees Celsius and the average time he lets each one cook is around 90-100 minutes.

After the yakiimo are finished baking, they are moved to the warmer just behind the oven. Apparently, while many other yakiimo trucks bake their products with hotter ovens in a shorter period of time, Okuno believes baking over a longer period under lower heat is much more effective for the best-tasting yakiimo.

While other yakiimo I’ve had come with the skin peeled off, Okuno properly washes the dirt off the skin so he can sell the yakiimo with the skin still intact, which adds to the taste and texture of the delectable baked snack.

So, the next time you're walking around the streets of Japan, especially in the winter season, we encourage you to keep an eye out for one of these trucks so you can treat your palate to some delicious yaki imo!

- Tokyo (Katsushika Ward, Edogawa Ward, Sumida Ward, Adachi Ward); Chiba Prefecture (Ichikawa City, Matsudo City); Saitama Prefecture (Misato City, Yashio City)
- On request, can make a special appearance, provided there is a landmark (hotel, building, etc.) nearby; requests should be made via website.

Hours: From 2PM - 8PM Saturdays, Sundays and national holidays

Dates: Every year from November until April

Links
- Website: https://annou-haruka-silksweet.jimdo.com/
- Twitter: @annouharuka