In a world where humans have various abilities and coexist with various races, Kale is a boy who has been treated as incompetent due to a lack of an ability. After helping a vampire princess, Kale discovers that his ability allows him to become the strongest of any genus once blood is shared. This power allows him to adapt to the characteristics of any of the races. With this power he has the potential to become the king of all races, which draws the attention of all the races whether their intentions are good or malicious. Thus, the one once called the weakest incompetent will become the world's strongest!!

Leon is a failed red mage who constantly fails class changes - as a result, he acts as a support for his adventuring team, Wolf Fang Sword. Eventually, he is fired from the party for not being strong enough. However, after leaving the team, Leon finds that he was stifled by his own team. The fact that he has a "Sage" class was unprecedented, and it turns out that he can fight perfectly fine on his own. Not to mention that his Sage class has a hidden power which only activates in certain conditions...

Early 20th century-behind the remarkable development of science and technology, humankind has built a solid magical civilization. "Salem Witch Academy" is an institution that trains "magicians" who even influence the power balance of the world. Tsuchimikado Haruei, a brilliant magician, stands in the United States to resolve the mysterious case that occurred there! ──Norse mythology, necromancy, vampires, and various magical systems can be blown away with oriental magic! High-end magic battle fantasy opens here !!