The Master of Ragnarok & Blesser of Einherjar: Leafa

She's the spitting image of Mitsuki. Aside from hair-color, nobody can tell them apart, and the two don't meet until the end of episode 12.

The Master of Ragnarok & Blesser of Einherjar: Mizuki Shimoya

Yuuto's childhood friend whom he has a crush on. She is able to call Yuuto using the phone he still possesses while he is close to the divine mirror that summoned him to Yggdrasil. When Yuuto is returned to the 21st century, while she is ecstatic, it doesn't take long for Mitsuki to realize Yuuto wants to go back, so she resolved to go with him. After managing to convince Yuuto that she won't back down on her resolution, she accepts Yuuto's marriage proposal.

The Master of Ragnarok & Blesser of Einherjar: Siegrune

One of the Wolf Clan's Einherjars and Yuuto's sworn daughter. She fights using a katana given to her by Yuuto and her rune enhances her strength. She greatly admires Yuuto, desiring his praise and causing her to be very protective of him. This eventually causes her to develop feelings for him.

The Master of Ragnarok & Blesser of Einherjar: Linnea

The patriarch of the Horn Clan who became Yuuto's sworn younger sister after her clan was conquered by the Wolf Clan. She is a hereditary patriarch, which is illegal in the technocratic Yggdrasil. Considering herself unworthy to lead, she proposed to marry Yuuto and unify their clans with him as patriarch. Despite her proposal being diplomatic, she eventually develops a genuine affection for him.