百炼霸王与圣约女武神

戦乱の黎明世界「ユグドラシル」に迷い込んだ現代の少年、周防勇斗。弱肉強食、幾多の氏族が覇権を争うこの世界で、勇斗は現代知識を武器にわずか十六歳で数千もの軍勢を率いる宗主（パトリアーク）にまで昇り詰めていた！異世界で王になった少年と、盃の契りを結び彼に絶対の忠誠を誓う麗しき戦乙女たちが織りなす、爽快無双ファンタジークロニクル！

戦乱の黎明世界「ユグドラシル」に迷い込んだ現代の少年、周防勇斗。弱肉強食、幾多の氏族が覇権を争うこの世界で、勇斗は現代知識を武器にわずか十六歳で数千もの軍勢を率いる宗主(パトリアーク)にまで昇り詰めていた!異世界で王になった少年と、盃の契りを結び彼に絶対の忠誠を誓う麗しき戦乙女たちが織りなす、爽快無双ファンタジークロニクル!!

Some urban legends are best left untested! Yuuto Suou gets more than he bargained for when he joins his childhood friend Mitsuki Shimoya in testing out an urban legend. When he uses his phone to take a picture of himself with the local shrine's divine mirror, he is whisked off into another world—one heavily steeped in the lore of the old Norse myths.

Using his knowledge gained from school and from his solar-powered smartphone, he has the chance to bring the Wolf Clan, the same people who cared for him, to prominence, all while earning the adoration of a group of magic-wielding warrior maidens known as the Einherjar.

(Source: J-Novel Club)