The successor issue divided the domains into two factions in fierce conflict with each other: One was the Hitotsubashi family supporting Yoshinobu HITOTSUBASHI who had a great reputation for intelligence and was the seventh son of Nariaki TOGUKAWA, the previous lord of Mito Domain; and the other was the conservative Nanki group supporting Yoshitomi TOKUGAWA (later Iemochi TOKUGAWA) who had a close genealogy with the current Shogun and was the lord of the Kishu Domain because of regarding blood line as important.
前水戸藩主徳川斉昭の七男・一橋慶喜は英明との評判が高く、これを支持し諸藩との協調体制を望む一橋派と、血統を重視し、現将軍に血筋の近い紀州藩主徳川慶福（後の徳川家茂）を推す保守路線の南紀派とに分裂し、激しく対立した。