Enjoy a Classic Breakfast at Kagurazaka Musubiya, A Shop Tucked Away in the Back Streets of Kagurazaka

Omusubi rice balls have been gaining attention recently both in Japan and around the world. But before the current omusubi trend, one beloved omusubi shop has been operating along a back street in Kagurazaka, a place that still retains some of the atmosphere of a traditional geisha district and is known as the Paris of Tokyo. Managing the shop, Kagurazaka Musubiya, is Ito Atsuko, who is also a mother of four. While raising her children, Ito came to appreciate the complexity of omusubi, and eventually wound up running a shop specializing in omusubi. We visited Kagurazaka one morning to try the shop’s uncompromising omusubi, one of the mainstays of Japanese food.

The eye-opening secret: How omusubi are formed determines how good they will taste

Kagura Koji is the first alleyway you reach as you walk up Kagurazaka Shita, and along this alleyway is Kagurazaka Musubiya, a specialty omusubi shop run by Ito. The shop opened its doors on January 1, 2016. In Kagurazaka, which has a reputation as a night spot, the shop is an invaluable place where you can enjoy Japanese food from early in the morning. The area is bustling with business people on their way to work, students on their way to neighborhood schools, and local residents.

The restaurant is easily spotted just after entering Kagura Koji by its round sign

The shop’s designer came up with the idea of using an omusubi-shaped door handle

Ito’s original inspiration to open an omusubi shop was a complaint by her sons: “Your omusubi don’t taste good.”

“I often used to make bento lunches for my kids for their sports and study activities. But when I put omusubi in their lunches, they wouldn’t eat them. Even my oldest son who loves white rice. Since serving egg and natto [fermented soybeans] with a bowl of white rice usually satisfies them, I was surprised when they told me: ‘Your omusubi don’t taste good’. I wondered what they meant by not tasting good: I mean, all an omusubi is is a rice ball formed around the filling. Around that time, I visited an omusubi shop that my husband used to frequent when he was a student, and I was struck by just how delicious they were. They were completely different from my omusubi. That inspired me to make omusubi that were equally delicious. At the time, my youngest was still in kindergarten, so what I ended up doing was training how to make omusubi at a nearby omusubi shop from 4 a.m. to 8 a.m. in the morning.

Ito Atsuko, owner of Kagurazaka Musubiya

The singular motivation for Ito, in the midst of raising her kids, was the desire to feed her children delicious omusubi.

“The very first thing I learned was how to form the rice balls. It was completely different from how I had been doing it. I had been squeezing the rice with quite a bit of power to form the balls. I thought I had to use so much force to ensure the rice balls wouldn’t lose their shape and come apart. But truly delicious omusubi are made with just the right amount of pressure, so that they slightly crumble when you take a bite. The way you form them is like gently wrapping them in seaweed.”

Two popular choices are the ooba beefsteak plant and whitebait omusubi and the spicy mentaiko cod roe omusubi. The secret to their delicious taste is their light, crumbly texture.

Ito says she has always loved eating. She had always dreamt of having a small restaurant someday, but she never imagined she would open an omusubi shop.

“My husband’s grandmother had run a Japanese restaurant in Kagurazaka, so we had connections to the area. I also made more and more friends in Kagurazaka through my kids, and an acquaintance introduced me to a property that had become available and suggested I open a shop there. My husband told me, ‘You’re studying about omusubi, so why don’t you open an omusubi shop?’ I had been studying omusubi for my kids, so the idea of opening a shop had never occurred to me. My kids were still small, and I didn’t think I could run my own shop, but my husband went ahead and signed the contract anyway. (laughs) It was the summer of 2015.”

Creating the menu started with searching for the best rice, seaweed, and salt to make omusubi that are delicious both fresh and cold

The shop had been stripped down to the bare walls when Ito took possession, so she started building the shop essentially from the ground up.

“Since I knew absolutely nothing about building a shop, I got help from lots of other people. An acquaintance introduced me to a food coordinator and a shop designer, and women I met through my kids were an enormous help. What I made a point of was that my omusubi would still be soft and delicious even if not eaten right away. This guided my selection of rice that is delicious even when cold as well as its balance with seaweed and the fillings. I was introduced to a rice master at a first-class rice specialty shop in Waseda, and I had him make a blend of rice specifically for omusubi. After several test rounds, I had the rice master create an original rice blend that would gently come apart when you bite into it and that had an initial soft and sweet mouthfeel. We went to these lengths because rice is the difference maker when it comes to omusubi. I also vary how I cook the rice, adjusting the amount of water depending on the season. The next thing I decided on was the seaweed. I was connected to a seaweed vendor by a sushi shop owner I’d been introduced to. With the assistance of this vendor, I was able to find a high-end thick seaweed product with a deep aroma and a very rich taste. There were many options for the salt as well. But what I ended up going with was salt produced on the remote Okinawan islands of Aguni. The salt is full of minerals and nutrients and has a sweetness that isn’t sharp. Even if you sprinkle a lot of this salt on an omusubi, it won’t taste salty at all. The one problem is the salt has a little too much moisture. So we have to take an extra step at the end and heat the salt to boil off some of the moisture and then grind it up in a mortar before using it.”

The seaweed is thick and flavorful. It’s delicious both freshly made, when you can enjoy its crispy texture, and after it has had time to sit, when it has a moist texture.

Once Ito had settled on the core ingredients of her omusubi, she began selecting ingredients for the fillings. Today, her shop offers some 40 varieties of omusubi, but she began with around 20 varieties when the shop first opened.

“By that time, even my kids had come to love the omusubi I was making, so we got together as a family to work on the menu options. We talked about what kinds of omusubi fillings are possible and what kinds we would want to eat. I was a complete novice in the food industry, so I didn’t think about costs; my first priority was to make sure that the customers could enjoy delicious omusubi. We went to a Tsukiji fish market broker and bought ingredients that we could see with our own eyes and taste and say with confidence that they were delicious.”

One reason for the shop’s popularity is the simple and reasonable pricing structure. Standard musubi are 240 yen each, Special musubi are 290 yen each, and Premium musubi are 350 yen each.

After deciding on the ingredients, the menu completion was near. However, no matter how delicious the ingredients are, the omusubi can be ruined depending on how they are formed. Ito, given her personal experience with this, was obviously very particular about forming the omusubi.

“We serve freshly made omusubi in the shop. We use different forming techniques for omusubi served in the shop and for omusubi for takeout. Given that omusubi will lose moisture over time, we form the omusubi for takeout to be fluffier by adding a little air. This way, they are delicious even when eaten cold.”

The omusubi feel like they are softly wrapped rather than being pressed and formed

Three popular omusubi options freshly made and still warm. From the left, rich and flavorful egg yolk pickled in miso in the shop; select corn beef that lets you get the full flavor of premium corn beef; and oyako (salmon and salmon roe), which is packed with top-grade salmon roe and salmon grilled and flaked in the shop.

Since the omusubi are made to order for eat-in customers, you can enjoy freshly made omusubi any time

The indelible memory of a Japanese breakfast from childhood — miso soup, rice, and side dishes

Kagurazaka Musubiya is open from 8:30 a.m. to 2 p.m. Ito decided on the opening hours so she still has time to look after her kids. Now, the shop has become a familiar morning sight in Kagurazaka.

“Although we are on a back street, it’s a shortcut to the train station, so lots of people pass by beginning early in the morning. Some people buy take-outs, and others stop in to eat before going to work. There are also people who work night shifts, come here to eat breakfast, and then go home. We truly get all kinds of customers, so I was careful about planning a menu that would energize all of them, and miso soup was an essential part of that. Miso soup is part of my image of the breakfasts I ate when I was little. I make the soup stock with kelp and bonito. The soup ingredients change depending on the season, but I always add sesame paste as our secret ingredient. The sesame paste brings out the richness of the soup and makes it really delicious.”

The sesame paste adds a mellowness and fragrance to the miso soup

The deep-fried chicken side dish is also popular. You can order it to eat in the shop, or you can have it to go as a deep-fried chicken bento lunch. Like the omusubi, the deep-fried chicken tastes delicious cold as well.

Salt-flavored deep-fried chicken is coated in a crispy batter made with potato starch, which goes perfectly with the juicy chicken meat that is packed with umami flavor

“I mentioned earlier that my husband’s grandmother ran a Japanese restaurant. In all honesty, though, we are a trueborn family of gourmets. We understand what is really delicious. We source our chicken from Miyagawa Shokucho Keiran, a poultry and egg vendor in Tsukiji. We deep fry the chicken in a sauce made from homemade salted koji [rice malt]. Just like with the omusubi, in the back of my mind is the desire to feed kids delicious, healthy food. I came across salted koji, a fermented food, and I’ve been using it regularly ever since. There are lots of deep-fried chicken flavored with soy sauce, but not that many flavored with salt. But the salt flavor goes well with our mainstay omusubi. I use potato starch in the batter because one of my kid’s friends has a wheat allergy.”

Expanding connections and bringing Japanese breakfasts to the world: A shop that is always a place where everyone feels at home

Ito’s world has expanded dramatically from omusubi, which she started making to please her kids. What are her goals for the future?

“It’s because of the support of so many people that I’ve been able to continue this long. So I really want to give back to the community and to the people involved with the shop. For example, the baskets we use in the restaurant to serve omusubi are handcrafted following traditional practices from suzu bamboo that grows wild near the second station of Mt. Fuji. The delicate mesh pattern attracted my eye, so I had the baskets woven to fit omusubi. I’d like to share the wonderful, old traditions of Japan with as many people as possible.”

The omusubi serving baskets are made from suzu bamboo. The color deepens with use, which adds to their charm.

“Eight years have already passed since I opened the shop. There have been changes pre-pandemic and post-pandemic. Before the pandemic, many customers were business people, but recently we’ve had lots of younger customers who are willing to line up and wait in the mornings. There are more inbound customers as well. There is a couple who are regular customers who actually come all the way from Hong Kong just to eat here. I’d like to convey the magnificence of healthy and delicious Japanese food to more people from other countries. My sister has been helping out in the shop for the last few years, and we and all the staff are mature women. (laughs) I want to be like a mother to everyone, so I want this to be a place where people of all ages can casually drop by and relax. I realize now that this is the kind of shop that I had always wanted. Nothing would please me more than to continue being a place for everyone — through delicious omusubi.”

Ito received a pair of charming earrings in the shape of omusubi from her family