Summoned unexpectedly to the world of Aletia from modern-day Japan, Hiro Oguro realizes this isn't his first visit. Once known as the Hero King Mars, he ruled battlefields, conquered lands, and established the vast Grantzian Empire before forsaking his memories to return home. Now, a millennium later, he finds his legacy threatened. The empire teeters under a belligerent ruler as ambitious royals vie for dominance and foreign powers ready for conflict. Encountering Princess Elizabeth von Grantz by chance entangles him in a ruthless struggle for the imperial throne, compelling Hiro to embrace his War God persona once more. Will he match the lofty expectations of his own legend as Aletia beckons for his aid once again?