The Eldest Son's Slow Life

In this heartwarming tale, a young man finds himself reincarnated into another world as Rain, the eldest son of the Proud Lord family, a local noble household. Upon his rebirth, he is blessed with a natural affinity for magic, which grants him the ability to wield "synthetic magic" - a unique combination of attributes. Armed with this extraordinary talent, Rain sets out to create a comfortable life for himself in his territory, but his plans are soon derailed by the arrival of Fenrir's young companion, Shiro, whom he has adopted during a magical training session in the forest.