It's wise to heed caution when it comes to certain urban myths. Yuuto Suou learns this firsthand as he accompanies his childhood friend, Mitsuki Shimoya, in testing out one such legend. Taking a photo of himself with the shrine's sacred mirror using his solar-powered smartphone, Yuuto finds himself transported to a world where Norse mythology prevails. With his extensive knowledge of Norse legends garnered from school and his trusty phone, Yuuto finds himself in a position to elevate the Wolf Clan, who once nurtured him, while gaining admiration from the Einherjar, a group of magic-wielding warrior maidens.