Ootoya was firstly established in 1958 by Eiichi Mitsumori in the name of “Ootoya Shokudo” at Ikebukro, Tokyo. All menus were sold in one price that were 50 yen; thereby, people knew here as “¥50 Shokudo”. Ootoya cites from a grape garden of Mr. Mitsumori's father and literally means “a great door” in Japanese like a great door that welcomely opens for all customers.

In 1979, the eldest son of the chairman, Mr. Eiichi Mitsumori, who is currently the chairman of Ootoya whose name is Mr. Hisami Mitsumori as the second successor. Ootoya was established as Ootoya Corporation on May, 1983. However, here is still a Japanese home-made-style restaurant with good quality and fair prices.

At the present, there are 250 branches in Japan and expanded abroad. Thailand was the first place. J Avenue Thonglor Branch was launched on January, 2005 and later in Taiwan, Hong Kong, Indonesia and Singapore. There are more than 40 branches in Thailand.