In the 1993 OVA series "Konpeki no Kantai" (lit. "Deep Blue Fleet"), instead of dying in the plane crash, Yamamoto blacks out and suddenly wakes up as his younger self, Isoroku Takano, after the Battle of Tsushima in 1905.
In the 1993 OVA series "Konpeki no Kantai" (lit. "Deep Blue Fleet"), the original timeline proceeds until Yamamoto's death in April 1943. However, instead of dying in the crash, Yamamoto blacks out and suddenly wakes up as his younger self, Isoroku Takano, after the Battle of Tsushima in 1905.