From Mar 5, 2026 to Mar 9, 2026, the corresponding solar term in the Nijūshi Sekki (24 solar terms) is 啓蟄(Keichitsu), and the corresponding microseason in the Shichijūni Kō (72 microseasons) is 蟄虫啓戸(Sugomorimushi to wo hiraku).

What Is “Sugomorimushi to wo hiraku” (蟄虫啓戸)?

"Sugomori Mushi To wo Hiraku" (蟄虫啓戸) is one of the Shichijūni Kō (72 microseasons), Japan's traditional system for marking the passage of the year. It falls each year from around March 5th to March 9th. Corresponding to the first microseason of "Keichitsu" (啓蟄) in the Nijūshi Sekki (24 solar terms), this period is described as the time when insects that have lain dormant in the earth throughout winter begin to sense the warmth of approaching spring and crawl up out of the ground. "Sugomori Mushi" (蟄虫) refers to insects sheltering through the winter, while "To wo Hiraku" (啓戸) means "to open a door." Taken together, the phrase poetically captures the image of insects awakening from hibernation and opening their door to the world — rendered in the lyrical language of the seasons. During this period, it is not only insects that stir: plant buds begin to swell and wild birds grow more vocal, as the natural world as a whole starts its shift toward spring. As temperatures gradually rise and the soil softens, familiar creatures such as earthworms, ladybugs, and cabbage white butterflies begin to make their appearances. The Shichijūni Kō (72 microseasons), long rooted in Japanese tradition, is a further refinement of the Nijūshi Sekki (24 solar terms) introduced from China, dividing each solar term into three parts and expressing the subtle transitions of nature in poetic language at roughly five-day intervals. Among these microseasons, "Sugomori Mushi To wo Hiraku" stands out as one of the most vividly life-affirming — a moment that symbolizes the stirring of life itself as it moves from winter into spring. "Sugomori Mushi To wo Hiraku" invites us to experience the arrival of spring through the eyes of the insects beneath our feet. Even amid the busyness of daily life, pausing to notice the small changes happening at ground level may offer a fresh sense of wonder at the richness of Japan's four seasons.

List of Japan’s 72 Microseasons