The Obama Han had taken care of learning since Tadakatsu's days and also invited many scholars of the Zhu Xi school of Neo-Confucianism as the government school.
Tadamochi, who was the seventh generation of the feudal lord of Obama Han, studied under the scholars of Jinsaigaku group and invited Kakuzan Ono who was the second leader of Boushoken, as regard to the recommendation from Shunsui Yamaguchi in Genbun 5(1740). After Kakusan died in Meiwa 7 (1770), He invited Bokuzan, the fourth leader, and found the Han school "Jyunzoukan" in Anei 3(1774). The school name comes from the Chinese writing.
It was repaired in Kyowa 2(1802), and this gate was built in Tenpo 5(1834). It is the Yakui gate and Kiridumadukuri and tile roofing and main parts were used with Hinoki tree. It is non-decorated and simple. After some repairing, its form has been changed, but there are gorgeous Namako walls and gargoyle which has the family crest of Sakai family and it is still valuable as the only one data which tells the learning in Obama Han and its history.