Founded in 2000, Wonderwall is an interior design company that operates from Tokyo, Japan. However, it accommodates clients from Europe, Australia, and the US. Moreover, it does a lot of work for various companies throughout Asia. By 2016, Wonderwall had completed over 400 projects. They ranged from flagship retail outlets to second-hand stores and chocolate shops. Today, it handles architectural direction as well. The company achieved its success by pursuing an unconstrained approach in its work. For example, it fuses traditional design philosophies with conventional ones. This fusion includes mixing minimalistic styles with science fiction or high culture with youth culture.

Some of its most prominent works include the Emporium in Melbourne, Australia and the Hyundai Travel Library in Seoul, Korea. In fact, the architectural design of the Emporium was so captivating that Architectural Digest listed it as the most beautifully designed malls in the world. It deserves that honor because it looks incredible. For example, the travertine flooring adds prestige and style to the mall because it has a soft palette of colors and it appears natural. The ceiling has faceted gold panels creating a sense of wonder and royalty as one walks through the mall. The Travel Library in Seoul is also impressive. For instance, the first floor contains a sitting and reading area that has chairs collected from different regions of the world. This collection creates a sense of cultural diversity in the Travel Library emphasizing the theme of the building, i.e., traveling.

The man behind all of this creativity is Masamichi Katayama. He co-founded H. Design Associates in 1992 with Tsutomu Kurokawa. One of his first projects was for a brand known as Nowhere. That was back in 1993. In 2000, Katayama started his design firm, Wonderwall. By 2015, he had completed 60 retail outlets for A Bathing Ape, which is a Japanese clothing chain. Moreover, he oversaw the interior design work for flagship retail stores owned by Nike, Uniqlo, Fred Perry, and Thom Browne. Today, Wonderwall is still expanding thanks to Katayama's vision, inspiration, and leadership.