Katōmado Window
This bell-shaped style of window is characteristic of Zen Buddhist temples. The design, known as katōmado, was introduced to Japan from China along with Zen Buddhism in the thirteenth century. Chinese-derived Zen architecture such as katōmado windows soon came to be associated with social status and refinement, and by the sixteenth century, samurai and daimyos were having these windows installed in their castles and residences.
Matsumoto Castle has four katōmado windows: two in the Southeast Wing and two on the fourth floor of the Northwest Tower. Their window sills have internal rain gutters to channel rainwater to the outside when the shutters are closed.