一名在半夜喝酒的男子，一觉醒来竟发现自己变成了小孩。而且自己还从此成为异世界贵族家的五男，连恩。尽管这突如其来的状况让男子不知所措，但由于一直以来对魔法怀抱的憧憬，加上不需要工作，因此男子很快便开始享受起这份能尽情练习魔法的愉快生活。
而似乎拥有魔法天份的他，不仅迅速学会了属性魔法，还陆续学会如何召唤精灵并获得优秀从魔，甚至藉由「道具箱」、「异空间」等魔法盖起房子，无论多么困难的魔法都能迅速精通。
为了从注定没落的贵族家独立，而成为冒险者的男子，曾几何时已是世界首屈一指的魔术师，甚至还成为了地位更胜从前的大贵族。以最强贵族为主角，逍遥随性的魔法奇幻故事！

Maki Maehara, the class outcast, finally makes his first friend: Umi Asanagi, the second-prettiest girl in class and the center of everyone’s attention. He’s convinced she’s out of his league, but as their unlikely friendship grows, Maki starts to wonder…could there be more than just friendship between them?

High schooler Hibiki is transported to a monster-filled fantasy world, where he possesses only non-combat skills. However, through key encounters, he discovers hidden powers and embarks on an epic adventure.