Ossan, Tensei Shite Tensai Yakusha ni Naru

Tanaka Taro, a humble actor, is stabbed to death one day and reincarnates as a little girl named Yamashita Maki. With a newfound talent for acting, Maki becomes a child prodigy and transforms the lives of everyone around her. Get ready for the overwhelming impact she has on the world!!

(Source: Comic Walker, translated)