Here is a list of foods you want to eat in Japan.
TLDR;
Takoyaki
Takoyaki, a popular Osaka street food, is a ball-shaped snack made of pancake batter filled with octopus ("tako" in Japanese) and pickled ginger. It's typically topped with takoyaki sauce, mayonnaise, and bonito flakes. Be careful when eating, as it's served very hot. We enjoyed takoyaki in nearly every city we visited during our trip. However, one of the best Takoyaki was in Nishik Market in Kyoto.
Okonomiyaki
Okonomiyaki is a savory Japanese pancake dish that's incredibly popular in Japan, especially in the regions of Osaka and Hiroshima. It's often described as a "Japanese pizza". In my opinion, It is the best way of eating cabbage.
Ramen
There's no comparison between instant ramen and a bowl of authentic ramen, especially when the broth is made by slowly simmering pork bones for hours. That's exactly what we had for our first meal in Tokyo, and it was absolutely delicious.
Yakitori
Yakitori, Japanese charcoal-grilled chicken on bamboo skewers, is commonly found in Izakayas and restaurants. We recommend the Torikizoku chain.
Udon
Udon is a type of thick Japanese noodle made from wheat flour. It's a staple in Japanese cuisine and is enjoyed in a variety of dishes, both hot and cold.
Sukiyaki
Sukiyaki is a Japanese hot pot dish (nabemono) that's cooked and served in a shallow iron pot, often right at the dining table. It's known for its sweet and savory flavor.
Unagi
A long-held desire to try grilled eel led us to Kyogoku Kaneyo in Kyoto, who has been serving grilled Eel for over 100 years. On the 1st floor, surrounded by traditional Japanese decor, we savored Unagi-Don and Kinshi-Don. It was an amazing experience.
EkiBen
Enjoying a bento box is a quintessential Shinkansen experience. Unlike local trains, where eating is prohibited, the sheer variety of bento options available at the station before boarding made me feel like a kid in a candy store.
Kobe Beef
Although dining on Kobe beef is the priciest meal you'll likely have, it's an unforgettable experience. We had our first taste of this exquisite beef during our Kobe visit, and the melt-in-your-mouth texture was simply divine.
Cheesecake
Those who have seen the iconic "jiggly cheesecake" will immediately recognize Rikuro's Namba in Osaka. This location offers a first-floor dining area where you can enjoy the treat on-site. Though slightly expensive, the experience is well worth the splurge.
Bakery
Sake
Japanese rice wine is a true delight! I had the opportunity to try a variety of sakes at restaurants and even picked up a few bottles at convenience stores. I found I mostly enjoyed sake served warm. During our time in Japan, I also enjoyed shochu, a distilled spirit with a higher alcohol content than sake. I have left the sake brewery for next time.