Magnus, the legendary Magic Knight, sacrificed himself to save humanity and was reborn as Arthur, a worthless illegitimate son of the Lorraine household. Devoid of any magical talent, Arthur was cast aside by his lord father, who regarded him as worthless trash. His mother endured endless humiliation while begging for medicine on his behalf. How will this reincarnated founding Magic Knight rise against all odds and lead his mother to a life of happiness?