The Master of Ragnarok & Blesser of Einherjar

Some urban legends are better left alone. When Yuuto Suou humors his childhood friend Mitsuki Shimoya by testing out a local myth, things take an unexpected turn. After snapping a photo of himself with the shrine's sacred mirror, he's suddenly pulled into another world-one deeply tied to ancient Norse mythology. Armed with his school knowledge and a solar-powered smartphone, Yuuto sees an opportunity to help the Wolf Clan, the people who took him in. Along the way, he finds himself gaining the respect of the Einherjar, a group of warrior maidens who wield powerful magic.