Founded in 1685 as a sub-temple of Zojoji, Hoshu-in houses an auspicious Buddha statue that was personally associated with Tokugawa Ieyasu, the founder of the Tokugawa shogunate.

During the devastating Tokyo air raids of WWII, Hoshu-in miraculously survived almost unscathed while the surrounding area was engulfed in flames, making it a renowned power spot at the base of Tokyo Tower.

Despite being a temple, Hoshu-in's strikingly modern architecture resembles a contemporary gallery or civic building rather than a traditional Buddhist temple, often confusing first-time visitors.

The temple features a unique "三すくみ" (san-sukumi) statue depicting the eternal standoff between snake, frog, and slug—a Japanese concept where each creature can defeat one but is vulnerable to another.