Kouritsuchuu Madoushi, Daini no Jinsei de Madou wo Kiwameru

Zeff Einstein dedicates his life to perfecting red magic and earns recognition for his skill. However, a newly developed spell exposes that red magic is actually his weakest ability. Frustrated by the realization that much of his effort was misplaced, he casts a spell to return his older self to his younger body. Joining him are Milly, a determined mage known as a genius, and Claude, an attractive swordsman. Together, they aim to study and master magic in a more effective way in this second chance at life.