Buddha's Birthday, also known as Hana Matsuri, "Flower Festival" (Japan)

Buddha's Birthday or Buddha Day is a primarily Buddhist festival that is celebrated in most of South, Southeast and East Asia, commemorating the birth of the prince Siddhartha Gautama, who became the Gautama Buddha and founded Buddhism. According to Buddhist tradition and archaeologists, Gautama Buddha, c. 623 BCE, was born at Lumbini in Nepal. Buddha's mother was Queen Maya Devi, who delivered the Buddha while undertaking a journey to her native home, and his father was King Śuddhodana. The Mayadevi Temple, its gardens, and an Ashoka Pillar dating from 249 BCE mark the Buddha's birthplace at Lumbini.

Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asian mainland, it is bordered to the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea in the south. The Japanese archipelago consists of four major islands alongside 14,121 smaller islands, covering 377,975 square kilometers (145,937 sq mi). Divided into 47 administrative prefectures and eight traditional regions, about 75% of the country's terrain is mountainous and heavily forested, concentrating its agriculture and highly urbanized population along its eastern coastal plains. With a population of over 123 million as of 2025, it is the 11th most populous country. The country's capital and largest city is Tokyo.