Yoshirō Mori
Mitsuzuka was a member of the Abe faction, headed by Shintaro Abe. The first head of this faction that occupies the right wing of the LDP was Nobusuke Kishi, who was succeeded by Takeo Fukuda.&lt;ref&lt;/ref&gt; Abe was the third head of the faction. Mitsuzuka was one of the "big four" in the faction consisted of he, Masajuro Shiokawa, Mutsuki Kato and Yoshirō Mori. On 20 June 1991, Mitsuzuka became leader of the Abe faction in the LDP, inheriting it after Abe's death in 1991. On the other hand, he and Mutsuki Kato toughly struggled over the control of the faction, resulting in Matsuki's removal from the faction in 1991. His election as faction leader led to the collapse of the solid coalition between the Takeshita faction, led by Noboru Takeshita, and Abe faction in the party. The Abe faction was later renamed as the Mitsuzuka faction under his leadership. His faction became one of the five influential factions in the LDP at the beginning of the 1990s. In December 1992, the faction was the largest one in the LDP with 73 members. In 1996, his faction was still the largest one in the party with seventy-four members. The control of his faction was assumed by Yoshirō Mori by 1999.