Kuro no Souzou Shoukanshi: Tenseisha no Hangyaku

A high schooler named Tsuguna dies prematurely due to a divine error and is granted a favor for his next life. Reborn into a noble family in a magical world, he possesses a unique ability to summon creatures, a power he requested from the god. His dark Japanese features are seen as a curse in this new world, and his magic develops slowly. Confined to a basement, he spends time reading his family's books. Eventually, he discovers the means to unlock his abilities and begins his journey with a summoned companion to enhance his skills.