day-after festival; night-after festival; smaller follow-up festival
Refers to a smaller festival held the day or night after the main festival (本祭り). Often less formal and more relaxed.
See also: 本祭
The day after the main festival ended, locals gathered for the day-after festival.
The follow-up festival is smaller in scale than the main festival, but the atmosphere is cozy.
Standard spelling for the smaller follow-up festival.
Abbreviated spelling; less common but seen in some contexts.
Compound of 裏 (ura, 'back', 'reverse side') and 祭り (matsuri, 'festival'), literally 'back festival', referring to the festival that follows the main one.