Considered to have taken a cue from an episode in which Zhi Bo during the Chunqiu period in China conquered Jinyang Castle by inundation, the inundation tactic was a clever idea which made full use of the merits of numajiro that was a swamp.
この水攻めの策は中国の春秋時代に晋(春秋)の智伯が晋陽城を水攻めしたことからヒントを得たと考えられ、低湿地にある沼城の利点を逆手に取ったまさに奇策であった。