The Master of Ragnarok & Blesser of Einherjar

Yuuto Suou's test of an urban legend with his childhood friend Mitsuki Shimoya goes awry when he uses his smartphone to take a picture of the shrine's divine mirror, transporting him to a world inspired by Norse mythology. With his knowledge of the subject and his solar-powered smartphone, Yuuto tries to elevate the status of the Wolf Clan, whom he considers like family, and earns the admiration of the Einherjar, warrior maidens with magical abilities.