The premier ancient temple in Eastern Hokkaido, Kokutaiji Temple, has been established as if embraced by Cape Barasan. The fact that Kokutaiji Temple has been famous as a cherry blossom viewing spot since ancient times might also be because Cape Barasan was protecting Kokutaiji Temple from the fierce waves and wind of the North Sea.

Kokutaiji Temple is one of the Ezo Sankanji (Three Official Temples of Ezo), whose establishment was decided in the first year of Bunka (1804) by the request of the Hakodate Magistrate, amidst the cries of crisis on the northern frontier, such as Russia's southward expansion and the harmful effects of the place contractor system in the late Edo period.

Most of the existing buildings have been renovated in later periods, but the temple grounds convey the ambiance of the Edo period, and 130,000 square meters, including Aikap in the back, have been designated as a national historic site as an important temple that played a unique historical role in Ezochi.

The temple grounds of Kokutaiji Temple are one of the leading cherry blossom viewing spots in Hokkaido, but among them, the one that is blooming particularly dark-colored flowers is the old cherry tree. It is an old tree, exceeding 180 years in age, which is said to have been transplanted from Ōshū Ishinomaki (Ishinomaki City, Miyagi Prefecture) by Akkeshi place contractor Yamada Bun'emon when the main hall and priest's living quarters were restored in the first year of Tenpō (1830), during the era of Bundō Genso, the fifth chief priest of Kokutaiji Temple. The Japanese name for this cherry tree is Ōyamazakura, and it has a height of approximately 10m, a trunk circumference of approximately 3m, and long branches extending in all directions.