The statuette is a representation of Shakyamuni, as he appeared at birth. It is called tanjo butsu zo (誕生仏像), the statue of Buddha at birth in the form of a miniature adult, standing, the left hand towards the ground, the right hand towards the sky to symbolize the unity of the world.

From this, the celebration has also come to be known as hanamatsuri (花祭り), or flower festival, an appellation coined by a Jōdo Shinshū priest in the Meiji era. The celebration is also generally named Kanbutsue (灌仏会, literally "Buddha bathing party"). Hanamatsuri is held in most of Buddhist temples in Japan, except those related to the Nichiren school.

The hanamidō consists of a basin of water containing a statue of the newly born Buddha. Visitors “bathe” the image with amacha (甘茶), a naturally sweet herbal tea made from a variety of hydrangea, while praying for the health of children and the general wellbeing of themselves and society.

Amacha is made from dried hydrangea, here seen decorating a small pool in the shape of the Buddhist svastika

During the Edo period, it was customary for celebrants to take amacha brewed by temples home to make ink with. This was then used to create a charm by writing a special phrase on a piece of paper referring to five great bodhisattvas (godairiki bosatsu), imbuing it with the ability to repel troublesome insects, among other magical properties.

Although kanbutsue is generally observed on April 8, some temples still celebrate the flower festival according to the traditional lunar calendar date, which corresponds to early May by modern reckoning.