Ohga lotus was found in 1951 by Dr. Ichiro Ohga, the researcher of lotus. With the help from the local junior high school students, Dr. Ohga excavated 2,000-years-old seeds of Ohga lotus from the blue mud layer just under the peat layer of Kemigawa, Chiba city. Later, Dr. Ohga has succeeded in re-cultivating the lotus, and this lotus was named after the surname of Dr. Ohga.
Ohga lotus is a large, single flower with the height of 1.5m and the diameter of 25cm. The tips of the petals are slightly curled inwardly and colored in light red. It does not have clear stria on its petals as well as the surface of the leaves.
Ohga lotus was planted in this lake Kozuki on April 26, 2002 with the support of Mr. Yozo Innami, the head of The Lotus Japan (the Japanese lotus society), who puts effort into the preservation of Ohga lotus. The donated six roots are potted and placed on the bottom of the lake to keep its pure pedigree.