From Sep 27, 2026 to Oct 1, 2026, the corresponding solar term in the Nijūshi Sekki (24 solar terms) is 秋分(Shuubun), and the corresponding microseason in the Shichijūni Kō (72 microseasons) is 蟄虫坏戸(Mushi kakurete to wo fusagu).

What Is “Mushi kakurete to wo fusagu” (蟄虫坏戸)?

"Mushi Kakurete To wo Fusagu" (蟄虫坏戸) is one of the Shichijūni Kō (72 microseasons), Japan's traditional system of seasonal divisions. It falls each year around September 28 to October 2. The Shichijūni Kō (72 microseasons) is a traditional calendar that divides the year into 72 subtle seasonal phases, capturing the delicate changes in nature throughout the seasons. Among these, "Mushi Kakurete To wo Fusagu" (蟄虫坏戸) marks a time that symbolizes the deepening of autumn. The term "Mushi" (蟄虫) refers to insects and small creatures that spend the winter underground, while "To wo Fusagu" (坏戸) means "to close the entrance." Together, the phrase describes the season when frogs and insects retreat into the earth and seal themselves away, beginning their long winter hibernation until spring returns. By this time of year, the chorus of insects that filled the summer air suddenly falls silent, and the fields and mountains grow still. Trees begin to display their autumn colors, the mornings and evenings become noticeably colder, and nature starts making earnest preparations for the coming winter. "Mushi Kakurete To wo Fusagu" (蟄虫坏戸) forms a seasonal pair with the spring microseason "Sugomori Mushi To wo Hiraku" (蟄虫啓戸), when hibernating insects emerge from their shelters. Together, these two microseasons reflect the keen observation of nature and the sensitivity with which the Japanese people have long appreciated the rhythms of the natural world—celebrating both the awakening of spring and the quiet descent into autumnal rest. By becoming familiar with Japan's traditional calendar, including the Shichijūni Kō (72 microseasons) and the Nijūshi Sekki (24 solar terms), one can gain a deeper appreciation for the subtle beauty of the changing seasons.

List of Japan’s 72 Microseasons