Higashine-no-Okeyaki, Special Natural Monument tree in Higashine, Yamagata Prefecture, Japan

Higashine-no-Okeyaki is a Zelkova serrata tree growing on the grounds of Higashine Elementary School in Higashine city, Yamagata Prefecture, Japan. The trunk is extremely wide and the branches spread far outward, casting shade over a large part of the schoolyard.

The tree was designated a Natural Monument of Japan in 1926, already acknowledged for its age and condition at that time. In 1957 it received Special Natural Monument status, the highest level of protection Japan grants to natural features.

Students at Higashine Elementary greet the tree daily and are called "keyaki-ko" (zelkova children); the school song mentions the great zelkova. Each 29 April, sixth-graders hang a shimenawa sacred rope on the trunk. A local belief holds that passing through the trunk's two-mat cavity brings children.

The tree stands on school grounds that are within walking distance of central Higashine. Visiting outside school hours helps avoid disrupting the daily routine of students and staff.

The trunk hides a hollow about the size of two tatami mats, with traces of an old campfire; a tradition holds that passing through it brings children, and a fence now blocks entry. In 2020 a snow-laden branch 70 cm thick and 11.7 m long broke off, and arborists judged the tree's vigour unaffected.