- Today was the first time that you saw the tree-shaped arch for yourself, how do you feel?

Kuma: What I was concerned about was its balance with the greenery of Meijo Park. Although we designed the arch in a tree-shape, to make the arena to be in harmony with the green forest of Meijo Park, I was anxious about how it would look in terms of scale. When I actually saw it, I was very relieved to see how well balanced it was and to realize that even human beings can create a forest.

- Where did you get the idea for the concept of "the arena surrounded by the tree-shaped arches"?

Kuma: I feel that IG Arena is the largest in Japan in terms of volume. The question was how can we turn this large volume into a human-like space, a space as familiar and gentle to human beings. That is why we produced the tree-shaped arch. The site of IG Arena is fortunately adjacent to Meijo Park, and the greenery is readily accessible. By attaching tree-shaped arches there, IG Arena will become one with the forest of Meijo Park and become a forest itself, too. That is the thought that led us to the tree-shaped arch.

- IG Arena will have its grand opening at the Nagoya Grand Sumo Tournament on July 13, 2025. I heard that you were also inspired by the old sumo huts.

Kuma: We are extremely excited that the Nagoya Grand Sumo Tournament will be held here. In the old days, sumo wrestlers used to wrestle under a timber framing. The idea that we might be able to bring it back to life in modern times gave us confidence in the architectural design.

Tree-shaped arches surround the arena 360 degrees.

Kuma checks the details of the finished product in the suite on the third floor.
Through this kind of repeated communication, a satisfactory space is completed.

- Did you have any other ideas before settling on the current design?

Kuma: The first thing that came to mind was a “tree” in the form of a tree arch, but there are many different shapes of “trees” and relationships between trunks and branches, so we studied a lot to find the best fit for Meijo Park. We used real trees to research the thickness, texture, and color of each tree, and finally came to the right one. This time, it was probably many times harder than usual (laughs).

- As for the tree-shaped arch, the way they jut out and the shape (thickness, length, and assembly) look different depending on the location where they are put around the arena. How many types are there in total, and what kind of ideas are there for the entrance, for example?

Kuma: There are three main types of tree-shaped arches, and we made them different because we wanted them to blend in well with each environment around them. At the entrance, to welcome visitors, a large overhanging tree-shaped arch is used to make people feel like they are passing through a big tree in a forest and raise positive energy.

- IG Arena has a capacity of 17,000 people, and it is an overwhelming space when you look inside, but it does not feel so intimidating from the outside.

Kuma: I think the reason it is not intimidating from the outside is the magic of the tree shape. The shape of a tree is divided into branches from the trunk, and as it is divided into thicker and thinner branches, it becomes increasingly delicate at the tip. I believe this kind of magic of layering that trees possess made the entire building gentle and somehow human.

- I have the impression that you are always challenging yourself to do something new, but what about IG Arena?

Kuma: Until now, sports facilities have inevitably been large concrete boxes, and as arenas get larger, they become very intimidating, but we considered the way to make them more human-like and decided to incorporate trees. I have no doubt that trees are the oldest friends with human beings who lived in the forest for a long period of time. The design of Japan National Stadium was the first time we attempted to incorporate trees into a sports facility, but we wanted to create an architecture that evokes memories of the time when human beings lived in the forest. I thought that no one had yet tried an architecture of the memories of the primitive human beings, and that was the biggest challenge.

- Lastly, I read an episode in your book that you listened to Yumi Matsutoya (a famous Japanese singer) in a tent every night during the field research in Africa in graduate school. Is there any event that you would like to see at IG Arena?

Kuma: This space is extremely flexible, so I am sure that we would be able to see something with an amazing sense of scale and speed that I have never imagined. I would like to see events that will blow my mind, and at IG Arena, there would be a lot of events like that.

The first-floor concourse has "tree shaded ceiling" designed by Kuma. The interior of the arena also features a mechanism that blends in with Meijo Park.