Japanese snowball; Viburnum plicatum
A deciduous shrub with round clusters of white flowers. The name comes from the resemblance of the flower clusters to traditional handballs (temari). Rare term; more commonly called オオデマリ.
Japanese snowball flowers are blooming in the garden.
From 手毬 (temari, 'traditional handball') + 花 (hana, 'flower'), referring to the round flower clusters.