To the best of my knowledge, Kurosawa only made two sequels in his career. The first was a sequel to his debut movie Sanshiro Sugata. The second was Sanjuro (1962), a follow-up to Yojimbo. It wasn’t originally meant to be that way – Sanjuro was intended to be a straight adaptation of an existing novel, but the success of Yojimbo led to it being reworked, with lead character Sanjuro returning. It’s not unlike the many Die Hard sequels, each an existing treatment, reimagined with John McClane as the lead character (ironically, all except for the dismal Die Hard 5, the only movie actually written and intended to be a Die Hard movie from the beginning).