The Half Breed Demons appear only in the manga between The Beasts of Maze Castle and Rescue Yukina arcs. They are gangs of half breed demons who want to start a gang war between Yusuke's junior high and that of a rival school. Once both sides have fought, they would defeat the weakened winners. As half breeds, they have human identities they are tied to, which limits them.
One of their leaders is a toad like demon who somewhat resembles Yusuke in his human form, while the other leader is a dark skinned demon with claws and fangs, who somewhat resembles Kuwabara. Carrying fake name tags and attacking in the dark, they claim to be Yusuke and Kuwabara and attacked students from the rival school.
They then attacked Kirishima, Okubo, and Sawamura, and claimed to be from the rival school.
When Yusuke and Kuwabara (who were recovering from their battles and could barely move) tried to get revenge, along with vengeful friends of the rival school, Kurama appears (referencing Sailor Moon's Tuxedo Mask in the English manga), and revealed the gang of half breed demons who were hiding to ambush them. While the two leaders commanded their armies to attack, Hiei had beaten all of them up, claiming to have confused them for trash. Now helpless, the two leaders were beat up and stripped of their clothes and never appeared again.
Trivia[]
- Mazoku Yusuke being able to use Spirit Energy is in the anime only. There is nothing in the manga that implies Yusuke to be half demon like these characters because after Yusuke died a second time, his human heart stopped beating and should have a demonic core instead that replaced its function which implies his anatomy turned full demon. He isn't biologically a human anymore despite still living in the Human World at the end of the manga. Kurama is not half demon either but rather a demon pretending to be a human after choosing to stay with his mother. In the manga, it is said that his body will become full youkai in a few years. So after he is already capable of leaving, he should be a full youkai already. He only chose to stay out of sentimental attachment. Youkai and human categories aren't based on anatomy but energy because in folklore there are a lot of youkai that were human like Kuchisake-onna. Kurama was never able to use Spirit Energy and Yusuke only uses Spirit Energy as a Mazoku in the anime. No characters around him felt anything but demonic energy from him after his atavism but the anime has problems with following manga canon and consistency in coloring energy while the manga never had that distinction.
- In chapter 170 of the manga, Kurama states that many D Class demons were captured and brainwashed into doing evil deeds so that the Spirit World could step in as the Human World's protectors. Of those brainwashed demons, after they were arrested by Spirit World, they were executed. This could include the Half-Breeds as well.