Cinque Izumi is a 13-year-old half-Japanese, half-British (Celtic and English) human from Cornwall and the protagonist of the series. He is summoned to the alternate world of Flognarde, the Kingdom of the Biscotti Republic as Princess Millhiore's "Hero".
Cinque has indigo eyes, bright blonde hair, and fair skin. He's mostly seen smiling, frowning when he's thinking. His battle suit is the colors of white and dark gray on his jacket. All white cape with red on the opposite side. Black pants, a blue head ribbon, red bandages wrapped, one visibly seen around one of his arm, the other with a metal glove on it. His boots are gray, black, and red. His school uniform is a white button up shirt and dark gray pants with sneakers.
He has a cheerful and straightforward personality, always going at his own pace. Athletic and acrobatic, he loves sports as well. Cinque is not very bright and can be quite dense around girls, especially when he thought Eclair Martinozzi was a boy, but that part has slightly diminished as the story progresses.
Cinque is a first-year middle school student in Japan's Kinokawa International School prior to the summon. A highly athletic student who participated in the Iron Athletics, with his cousin, Nanami Takatsuki as a rival taking first place to his chargin. In Flognarde, Cinque becomes known time and time again as the Kingdom of the Biscotti Republic as Princess Millhiore's "Hero".
After the end of Dog Days', Cinque's relationship with Rebecca has similarly deepened. It is very likely the two were able to admit their feelings, although in Cinque's case, he naively believes that she means it in a friendly manner. Earlier in the episode, when asked by Couvert if he wished to marry either of them (or both), Cinque declared that he wanted to prove himself by defeating Nanami in competition before pursuing a romantic relationship.
- The voice actor of Cinque is by "Mamoru Miyano" who is also the voice actor of Tamaki Suoh (Ouran High School Host Club). In roles, both of them are very slow when it comes to their love life.
- Design-wise Cinque bears a strong resemblance to Erio Mondial from Magical Girl Lyrical Nanoha StrikerS, which was also made by Seven Arcs.