Ren has short hair and large emerald green eyes. He has apparently high altitude and seems to be very slim. His common garment consists of a pink coat with green trousers.
Ren is timid and polite, as well as a bit effeminate. These qualities lead to many people being protective of him. He seems easy to be saddened when Ayano insults Kazuma's character. Even despite his softness, Ren does not hesitate to help others when needed. Ren also does not want to fight unless provoked or if it is necessary.
Ren is first shown when he greets Ayano, and she makes upsets for her father when she sneaked in the past hour.
Ren begins to tell her that his brother has returned to Japan. Ayano tries to remember if Ren had a brother. Ren reminds her that his brother lost against her during the Enraiha inheritance ceremony. She remembers that she defeated him with one burst of magic. Later they both broke into a meeting with the clan boss, her father Jūgo Kannagi, Genma Kannagi and Shinji Yuuki. In the conference room, he learns that Kazuma is a wind magic user. Then he states that it is unbelievable that someone in the head family would become a user of the wind magic. The next day there is confusion in one of the branches of family households; three members of the unit were murdered. Hyoue Kazamaki claims that the victims were killed with the magic of wind stronger than his knights,
Despite his age and timidity, Ren is actually a very powerful fire magic user, his skills rivaling even that of Ayano, and then there's the matter of his intelligence, as seen when he turns sand into magma so that it cannot be used by Yuki.