Synopsis

Oneday,RyuseiHomuraandallhisclassmatesaretransportedtoanotherworldwheretheyareaskedtohelpindefeatingthe12DemonKings.Ryuseiwasalwayslookedatasanidiot,aweirdoandapervertwhoalwaysstaresatgirls’breasts.Hewasalwaysbulliedandbeatenupafterschool.Evenafterthesummoning,heendsupbeingtheweakestinhisclass.Andeventually,inthemidstofabattle:"Wedon'tneedtolookaftertrashlikeyou.You'rejustaburden,sodie!"Ryuseiwaskilledbyoneofhisclassmates.Aseverythingturnsdarkforhim,theDemonGodoffershimadeal:"Icangiveyouasecondchance.IwillmakeyouaDemonKing.Iwillgiveyoupower.Youwillbeabletogetrevengeandliveyourlifeasyouplease!"ButtherewasonethingtheDemonGoddidn'tmentiontoRyusei,andwhenhewokeup:"WHAT!?WhythehellamIaloli!?"NowRyuseimustliveastheDemonKingofInsanity,MillaWalpurgis.