Haikei Yuusha-sama. Youjo ni Tensei Shita no de, Mou Kuni ni wa Modoremasen! Densetsu no Majo wa Nidome no Jinsei demo Saikyou deshita

Court magician Agnes sacrifices herself to protect the hero Kevin from the Demon Lord's army. At the brink of death, she casts a reincarnation spell on herself, successfully avoiding death, but is reborn as a three-year-old girl named Rita living in the countryside! With the same knowledge and magical power as in her previous life, she stirs up all sorts of trouble... Will the day ever come when the reincarnated Agnes and the hero Kevin meet again?