About three decades prior to start of Hagure Yuusha no Aesthetica, a number of selected people from Earth were summoned to other worlds just about 50 % of them having the ability to return. One of many young adults chosen was Akatsuki Ousawa, who was simply delivered to Alayzard to defeat the Dark Lord Garius, which he did, before returning to his original world. A number of the successful chosen ones cut back little trinkets as souvenirs. Akatsuki, on the other hand, went a different route%u2014he brought back the defeated Dark Lord's daughter, Miu, that's now posing as his most loved little sister!


Upon returning, Akatsuki and Miu have to enroll in a special school called BABEL where they must train to at least one day master the powers they gained in Alayzard, confident that they may eventually be able to serve mankind. Will Akatsuki and Miu be able to keep her true identity a secret or will their want to live peaceful lives together climb in flames?