Elma

 Elma (エルマ Eruma) is a female dragon from the Dragon Faction of Order, the opposing faction of Chaos, which Tohru belongs to. She adopts the name Elma Joui (上井 エルマ Jōī Eruma) as her human alias after she finds that she is unable to return to her world without Tohru's help.

She ends up working in the same office as Kobayashi, despite initially lacking the skills to do so.

Tohru
She appears to dislike Tohru in the sense that Tohru belongs to an enemy faction, hence their supposedly clashing ideologies. Beyond that, however, the two appear to be civil with each other as seen, for instance, during their preparation for a Christmas play, where Tohru invites Elma to Kobayashi's apartment to help out.

Kobayashi
Elma gets along well with Kobayashi and relies on her for advice after she applies for work in the same company as Kobayashi. As a token of gratitude, Elma decides to create a magical charm for Kobayashi and gifts it to her to pay the woman back for her kindness.

Fafnir and Lucoa
Though not much interaction is shown between Elma and the two other dragons, Elma seems to respect them, referring to them as Fafnir-dono and Lucoa-dono.