After the alliance killed Shuzo SERA, the chinbushi (temporary provincial superintendent), and began to engage in full-scale battles in Shiraishi-guchi, the nature of the alliance was changed to a military one.
新政府の鎮撫使（世良修蔵）を殺害し、白石口で既に本格的な攻防戦が開始されていたことから軍事同盟へと変化した。