My friend in Tatebayashi tells me, "The legend of the azalea park is that the lord of Tatebayashi, Sakakibara Yasumasa, had a mistress named Otsuji.
The wife was jealous of her and gave her such a hard time that Otsuji threw herself into Lake Jonuma and died. Since her name sounded like tsutsuji, the lord planted the garden to console her soul."