Haruna is a Masō-Shōjo from Villiers who wields a chainsaw named Mystletainn(ミストルティンMisutorutin?) and battles demons known as Megalos. She can also use her magic to repair damage caused from her battles and erase people's memories, the latter ability which becomes useful to Ayumu at the end of episode 1 (as revealed in episode 2). She was originally ordered by her teacher, Dai-sensei, to go to Kyoto to get some tofu, but she ended up in Tokyo instead. After first encountering Ayumu following a fight with a demon, her magical powers are absorbed by him, due to the fact the magic Eucliwood used to revive him is stronger than hers. As she tries to figure out this situation, she appoints Ayumu to fight the Megalos in her place as a Masō-Shōjo and starts living with him. She is a good cook, though is usually limited to just making fried eggs. Despite being a self-proclaimed genius, she has trouble remembering people's names or important details of assignments, since she only remembers what she deems interesting and forgets everything else. Ayumu's name is an exception to this, suggesting that she cares about him. She appears to have some feelings for Ayumu, showing jealousy when he is close with Yuki and having a dream of kissing Ayumu. She is jealous of Mael for her relationship with Ayumu, even asking him to kiss her. Eventually, Mystletainn recognized her as its owner again, enabling herself and Ayumu to transform into Masō-Shōjos in tandem in time for the final battle against Yoruno.
When Iori Nomizu was asked which part of her was similar to Haruna, the character she was voicing, she stated that she and Haruna were both very energetic.
