The fugitive warrior Minamoto no Yoshitsune was attacked by his ostensible protector Fujiwara no Yasuhira, fourth lord of Hiraizumi, in 1189. Rather than face an ignominious death at the hands of his enemies, Yoshitsune killed his wife and children before gutting himself. When master haikuist Matsuo Basho visited Hiraizumi five centuries later, he was moved by the heroic life and tragic death of Yoshitsune and his retainers and composed the following famous verse:

The summer's grass
'Tis all that's left
Of ancient warrior's dreams

A stone monument in Basho's own hand can be found on the Motsuji grounds, along with the English translation by Morioka native statesman, Nitobe Inazo.