Haruhito was 15 at the beginning, and turned 16 in Episode 32.
Haruhito is very mature, nice, responsible and hard working. He also is good at sports.
Yume Hinata: Yume has a crush on Haruhito that he doesn't know about. After obeying the Queen of Nightmare, he started to get close to Yume. At the last part of the season, he showed his hostility towards Yume, but not after the Queen was purified.
Yuri Sawamura: Yuri is Haruhito's classmate and childhood friend. After obeying the Queen of Nightmare, he started to estrange himself from Yuri, but their relationship was back to normal at the end of the season.
Akihito Sugiyama: He is Haruhito's younger brother who is now studying in America. Due to Akihito's superior intelligence, Haruhito always feels inferior to him.
Kotoko Imai: Kotoko is Haruhito's classmate.
Yuni, Tsugi and Hagi: They are Haruhito's partners, after the Queen's interference. Before he knew about their partnership, Yuni and co. had lived in Haruhito's house for a while. Even though Yuni and co. always make mistakes, he is still kind towards them. After the events of the first season, he treats them as good friends.
The Queen of Nightmares: Making use of his inferiority towards Akihito, the Queen controls Haruhito to make him become a partner of Yuni's and interfere the purification of Black Abysses, as well as to steal Dreamy Stones. The reason the Queen chose him is that his experience is similar to hers.
Haruhito is the president of the boys' tennis club and the student council who is popular in school that he has his own fan club. He later retires from the tennis club and the student council, and passes the title of the president to Keigo (tennis club) and Suzuko (student council).
Starting from Episode 24, making use of his inferiority towards Akihito, Haruhito is controlled by the Queen of Nightmares and becomes Yuni's partner. Obeying the Queen, he begins to interfere Yume and Mew's purification of Black Abysses, as well as to steal Dreamy Stones. However, Haruhito gradually gained his conscience back because of the charm Yuri gave him in Episode 33; thus, the Queen inserted a Black Abyss into him in Episode 37, making him completely be on the Queen's side.
At the last part of the season, he showed his hostility towards Yume, and was about to erase her memories with Mew, along with his. After being interfered by Rei and Asahi, he went to the grassland of his memory, suffering from losing his precious memories. He fell into a coma after striving to keep his memories. At the end, it was Yuri's wish and her charm that awakened him, making him back to normal.
- The name Haruhito means "distant" (遼) (haru) and "compassionate" (仁) (hito).
- Haruhito's surname Sugiyama means "cedar" (杉) (sugi) and "mountain, hill" (山) (yama).
- He has the same birthday as Asahi.
- In Episode 16 it's reveal Haruhito goes to a cram school called Great Private School but since his grades are so good he will be going to the Great Alpha Private School.
- In Episode 37 it is revealed that in Haruhito’s dream that he got first place in a kindergarten fire truck drawing contest.