まめぞう
At the intersection of Sotobori Street and Roppongi Street, one block east of the Tamachi Intersection, stands the General Patent Office building of the Ministry of Economy, Trade and Industry. Upon entering the main entrance, you need to fill out a visitor reception ticket at the registration counter on the left, then proceed through the automatic door, present your driver's license at the reception on the right, receive a temporary pass, and go down the spiral staircase in the center. After touching the pass at the gate, you can enter safely.
As you descend, you can see a cafeteria-like dining area from above. I had heard that there were three dining halls: "Ataburu" (https://tabelog.com/tokyo/A1308/A130802/13130291/), "Nagatomo" (https://tabelog.com/tokyo/A1308/A130802/13209793/), and "Aratano" (https://tabelog.com/tokyo/A1308/A130802/13188536/), but there was only one. I later learned that the second and third halls closed at the end of March 2022, and a new restaurant called "Restaurant BONO" opened in April.
The facility has quite a bit of history. There are around 20 menu items available, including set meals, noodles, and curry. On the day of my visit, the set meals were "Pork Bulgogi" (510 yen), "Sardine Fry and Chicken Cutlet" (510 yen), and "Omelette" (630 yen). I selected the "Value Lunch 510 yen" on the ticket machine, paid with my PASMO card, and then proceeded to the cafeteria lane to choose side dishes.
After enjoying my meal, I separated the trash, placed the chopsticks in the water-filled container, returned the tray to the return lane, and said thank you. In the early 21st century, when my office moved from Ikejiri-Ohashi to Kamiyacho, finding a lunch spot was quite a hassle. I found a blog that introduced lunch spots in the Tamachi, Toranomon, and Kamiyacho area, created by a blogger named "Jonii." He meticulously walked around the area, pasted store information on his self-made map, and introduced it in an easy-to-understand manner. After being featured on an NHK documentary, Jonii's blog was completely closed down, and he disappeared. It's a shame. I wonder if he is now quietly having lunch in this cafeteria.