Why Has Inokashira Park Pond Turned Matcha Green?

A pond at Inokashira Park, a popular destination in Tokyo's Kichijoji area, has turned a striking matcha-like green, a phenomenon that has become particularly noticeable in 2026 and is believed to be caused by an accumulation of phytoplankton. The pond at Inokashira Imperial Gift Park, which spans Musashino and Mitaka cities, covers nearly 42,000 square meters. Shinichi Nakano, a professor at…