noun
children's sumo
Sumo wrestling performed by children, often as a local festival event or school activity.
秋祭りで子供相撲が行われた。
Children's sumo was held at the autumn festival.
息子は子供相撲の大会に出場した。
My son participated in a children's sumo tournament.
Refers to sumo in general, including professional sumo. 子供相撲 specifically denotes sumo performed by children.
Compound of 子供 (こども, 'child') and 相撲 (すもう, 'sumo').