It is said that the name of 'Aku shichibe' came from the suspicion he had against his uncle who he killed, Dainichibo Nonin who harbored him, after he was defeated in the battle of Dannoura.
壇ノ浦の敗戦後に自分を匿った叔父の大日房能忍を疑心暗鬼にかられて殺害してしまったためにそう呼ばれるようになったとの伝承もある。