Nestled in Tokyo’s Minato Ward, the Arimaston Building is a striking testament to the vision and perseverance of architect Keisuke Oka. Taking nearly 20 years to complete, this unique structure stands as a hand-crafted masterpiece amidst a city dominated by modern, machine-made designs.
The building’s whimsical appearance, characterized by twisting concrete walls and polygonal windows, evokes the feel of a fantasy realm, often compared to Studio Ghibli’s Howl’s Moving Castle. Oka began construction in 2005 with a clear goal: to challenge mass production in architecture. Using minimal resources, he mixed concrete by hand and improvised its design as he went, incorporating unconventional materials like food trays and plants into the formwork. Friends and collaborators contributed ideas, further enriching the building’s imaginative details.
Despite occupying only 40 square meters, the four-story structure (with an additional basement) embodies a sense of grandness through its intricate design and robust construction. The concrete mix was engineered for exceptional durability, estimated to last over 200 years. As part of its future, the building will be relocated 10 meters southeast in 2025 using a traditional Japanese method called “hikiya” to accommodate nearby redevelopment.
For Oka, Arimaston is more than a residence or studio—it is a statement against disposable culture. By embracing slow, deliberate craftsmanship, he hopes to inspire a deeper appreciation for the artistry and human touch in construction.
This building serves as a reminder of what’s possible when passion, creativity, and patience converge, offering a profound contrast to the rapid, mass-produced urban landscape of Tokyo.
