Onigiri Bongo has long been the most popular spot for onigiri in Tokyo, with at least a one hour wait in line to enter even on weekdays. If you don't want to wait in line however, you can order takeout over the phone.
The reason for their popularity is the wide variety of onigiri that they make. Although they also sell miso soup and 3 other small side dishes, the bulk of their menu consists of onigiri ranging from common types such as salmon flakes and natto to more adventurous options like bacon and cheese and mentaiko mayo cream cheese. We ordered from the Japanese menu but it appears they also have an English one so if they don't already hand it to you, ask for one!
Address: 2 Chome-27-5 Kitaotsuka, Toshima City, Tokyo 170-0004
The seating space is small, and you can watch them craft your onigiri right in front of you if you get the counter space.
would love to try this place!