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O/sio Overview


B1 Brick Square 2-chōme-6-1 Marunouchi, Chiyoda City, Tokyo 100-6990


+81 (0) 3-3217-4001


7 minute walk from Tokyo Station.
5 minute walk from Nijubashi-mae Station.

Operating Hours

Sun: 11:00AM-2:00PM, 5:00PM-9:00PM
Mon: 11:00AM-2:00PM, 5:00PM-10:00PM
Tue: 11:00AM-2:00PM, 5:00PM-10:00PM
Wed: 11:00AM-2:00PM, 5:00PM-10:00PM
Thur: 11:00AM-2:00PM, 5:00PM-10:00PM
Fri: 11:00AM-2:00PM, 5:00PM-10:00PM
Sat: 11:00AM-2:00PM, 5:00PM-10:00PM

Payment methods

Cash, Visa, Master Card, AMEX, Diners Club, JCB

O/sio Description

Located in the heart of Marunouchi, Tokyo, o/sio is a unique dining establishment that offers a fusion of natural wines, charcoal-grilled meats, and Italian cuisine. The restaurant's interior is tastefully decorated with gray tiled floors and tables in calming hues, creating an elegant and sophisticated atmosphere. The pendant lights hanging from the ceiling gently illuminate the tables, adding to the intimate ambiance of the evening.

What sets o/sio apart is its extensive selection of natural wines, making it the number one destination for wine enthusiasts in Marunouchi. The menu features a variety of dishes, with a focus on their specialty charcoal-grilled meats and Italian classics. Indulge in their mouthwatering dishes such as the succulent grilled Iwachu pork and the rich and flavorful Kokumito pasta. For those looking for a unique dining experience, o/sio offers a range of set courses that showcase the best of their menu, including a selection of appetizers, pasta, and main courses.

Whether you're a wine connoisseur or simply looking for a memorable dining experience, o/sio is the perfect destination. With its exceptional cuisine, inviting atmosphere, and extensive wine selection, this restaurant is a must-visit for anyone seeking a taste of the finest natural wines and delectable Italian dishes in Marunouchi, Tokyo.

Restaurant Features

Home Delivery

Take-out Available

Reservations Accepted

Wine List

Private Dining Room


Wheelchair Accessible

Stylish Interior

O/sio Reviews

O/sio Google Average Rating


O/sio Tabelog Average Rating



Enjoyed their variety of natural wines by glass. Food was tasty. Staff were friendly and accommodating. Overall enjoyed our experience.


o/sio is the more casual sister restaurant of the team behind one of my favorite restaurants and now one star Michelin, Sio in the Yoyogi Uehara neighborhood of Tokyo. The restaurant is located inside the basement of one of the many office buildings in the Marunouchi area and has a casual yet elegant vibe.

I have yet to try o/sio's regular menu, but this month they had a one month Yoshoku pop-up. Yoshoku is basically a popular Japanese adaptation of Western cuisine, which includes dishes like Napolitan pasta (pasta with ketchup sauce, sausages, and grilled vegetables), Doria (rice gratin with a creamy white sauce), and Omurice (an omelet filled with rice). We ordered the Doria with scallops and the Omu Napolitan (Napolitan pasta with a side of omelet). Each entree came with a small soup and a salad and cost 1000 yen and 1300 yen respectively, which was amazing for the quality.

We also had the option to add a cream soda for 300 yen and since I am a huge fan of the Japanese cream soda (melon soda with vanilla ice cream), I had to add it to my entree. You can upgrade the regular Japanese cream soda to the gold colored cream soda, which has a stronger melon flavor for an additional 100 yen.

The service here is really good, as one would expect from a sister restaurant of a Michelin restaurant. Since the restaurant is in an office area, I'm sure it can get pretty busy during lunch hours on weekdays, but I think this place has a quick turnaround since food comes out pretty quickly, making this the perfect place to enjoy great food even when you only have a hour before you have to go back to your desk. We went on a Sunday evening and it was definitely quieter and more relaxing so evenings may be better if you don't want to feel rushed.


Great little place


Translated from Japanese:

I think Kokumeat is the signature menu, but there are also a variety of dishes, including spicy mala and luxurious truffle cheese. Since it was my first time, I had the omelette meat. Although it is rich, it is surprisingly easy to eat and is very delicious...


Translated from Japanese:

Available for Saturday lunch, reservations required. The staff at the restaurant are very considerate and the food is delicious. I thought it would be close because there was another group sitting at the large table, but the flowers on the desk made it difficult to see, so I was surprised...


Translated from Japanese:

The service staff were very thorough in their explanations and pairings to match the dishes, and the food was delicious! I used it as a course for lunch, and the rich meat in the pasta was very delicious and impressive to me!

O/sio Map

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