For several years the Yamato Court made no attempt to re-assert itself, but in 527 an expedition of unprecedented magnitude was organized. It consisted of sixty thousand soldiers under the command of Keno no Omi, and its object was to chastise Shiragi and to re-establish Mimana in its original integrity. But here an unforeseeable obstacle presented itself. For all communication with the Korean peninsula, Tsukushi (Kyushu) was an indispensable basis, and it happened that, just at this time, Kyushu had for ruler (miyatsuko) a nobleman called Iwai, who is said to have long entertained treasonable designs. A knowledge of his mood was conveyed to Shiragi, and tempting proposals were made to him from that place conditionally on his frustrating the expedition under Keno no Omi. Iwai thereupon occupied the four provinces of Higo, Hizen, Bungo, and Buzen, thus effectually placing his hand on the neck of the communications with Korea and preventing the embarkation of Keno no Omi's army. He established a pseudo-Court in Tsukushi and there gave audience to tribute-bearing envoys from Koma, Kudara and Shiragi.
For the space of a twelvemonth this rebel remained master of the situation, but, in A.D. 528, the o-muraji, Arakahi, crushed him after a desperate conflict in the province of Chikugo.* Iwai effected his escape to Buzen and died by his own hand in a secluded valley. Although, however, this formidable rebellion was thus successfully quelled, the great expedition did not mature. Keno, its intended leader, did indeed proceed to Mimana and assume there the duties of governor, but he proved at once arrogant and incompetent, employing to an extravagant degree the ordeal of boiling water, so that many innocent people suffered fatally, and putting to death children of mixed Korean and Japanese parentage instead of encouraging unions which would have tended to bring the two countries closer together.
*In the Chikugo Fudoki a minute description is given of Iwai's sepulchre, built during his lifetime but presumably never occupied by his body. The remarkable feature of the tomb was a number of stone images, several representing grave-guards, and one group being apparently designed to represent the judicial trial of a poacher.