百錬の覇王と聖約の戦乙女

Junior-high student Yuuto Suou tests a local urban legend about the Tsukimiya Shrine's mirror and is torn away from his childhood friend Mitsuki Shimoya, waking up in a world modeled on Norse myth. Taken in by the Wolf Clan, he uses the smartphone knowledge in his pocket to help the clan survive and rises to lead it, earning the loyalty of the warrior maidens called Einherjar, Siegrune and Felicia among them. This manga adapts the original light novel.