Tsubaki Castle is a distinctive commercial and office complex completed in 2000, located in Oshima, Tokyo. Designed collaboratively by Nobumichi Oshima of Oshima Atelier and renowned architect Teruo Fujimori, this structure exemplifies innovative early 2000s Japanese architecture. Situated at 167 Wada, Nozomashi, the building showcases a unique blend of contemporary design principles and contextual sensitivity to its island setting. The project demonstrates the architects' commitment to creating functional yet visually striking spaces that harmonize with their environment. Tsubaki Castle stands as a notable example of commercial architecture from this period, reflecting the creative vision of two prominent Japanese designers.