A dispassionate, withdrawn assassin, Golden Darkness is hired by one of Lala's arranged suitors, Lacospo to kill Rito, until she breaks the contract, noting the true nature behind her target. Golden Darkness is currently staying on Earth, roaming around the city streets and Sainan High, with a motivation to continue her duty to assassinate Rito, although she has yet to accomplish this (hinting she only said this as an excuse to stay on Earth, which is then confirmed). Commonly referred as "Yami-chan", she spends her time reading books and magazines, while eating taiyaki (it was the only thing she ate on Earth since it was the first food offered by Rito, prior to spending a night at the Yuuki residence for a sukiyaki dinner). By her planet's calculations, she is 24 thousand years-old (as shown in season 1 where the job applicant stops Konjiki no Yami just before she was about to say 'thousand'), despite having the appearance of an 11-year-old (albeit a rather mature one), although this is only mentioned in the anime and has a weakness towards anything slimy. Like Lala, Golden Darkness' physical abilities are exponentially stronger than a human's. She carries a unique ability to turn her body parts into various objects through use of nano machines circulating her body, ranging from swords to dragon heads. Unfortunately, excessive use becomes a hazard to her health. She states she hates "ecchi" people, and does not hesitate to assault a person who looks at her in an obscene way, even if it's her own fault like when she was using her abilities to increase her bust she attacks Rito when he saw her, mostly out of embarrassment or for many occasions standing at the top of something such as stairs where her panties could be seen by accident. She has also stated, that she doesn't understand if she can feel love and all its wonders, though she slowly becomes closer to Rito once seeing that he is a good person.

Shinra is a Fire Officer Second Class and a Third Generation Ability User belonging to the 8th Special Fire Brigade. His ability permits him to emit flames from his feet. Twelve years before the start of the series he was held responsible for a fire accident in which his mother and younger brother was killed. He is often shown with an artificial and menacing-looking grin on his face. Because of this and his history, he acquired the epithet "Devil." His dream is to become a hero who protects everyone.