Outside of theme parks, it's unusual to see a massive, multi-story building with a design that's clearly based on a children's transformer-robot toy - it represents a rare match-up between an adventurous client and an innovative architect. And while it predictably appears on various "weird architecture" lists, the building is well executed and stays faithful to its concept.

According to the architect, "Architecture ought to be something capable of moving people's hearts and giving them a physical thrill in a way possible in no other art." The building was the first major work by architect Makoto Sei Watanabe, with construction completed in 1990.