noun
eve of a festival; festival-eve vigil
Refers to the evening before the main day of a Shinto festival, often involving a smaller-scale celebration or vigil. Compare 宵祭り (よいまつり), which is a similar concept.
See also: 宵祭り (よいまつり)
宵宮には、地元の人たちが集まって小さな神事を行う。
On the eve of the festival, local people gather and hold a small Shinto ritual.
明日が本祭りで、今夜は宵宮だ。
Tomorrow is the main festival, and tonight is the festival eve.
宵祭り also refers to the eve of a festival, but is more commonly used in some regions. 宵宮 emphasizes the shrine aspect (宮), while 宵祭り focuses on the festival (祭り) itself.
Compound of 宵 (よい, 'evening') and 宮 (みや, 'shrine'), referring to the evening before a shrine festival. The alternate spelling 夜宮 uses 夜 (よ, 'night') for the same reading.