Aijima Cecil was at first cheeky during the first parts of the Master Course, but once he realized he wanted to become an idol, he pulled himself together. Cecil often gives advice to the other members of ST☆RISH. He is very insightful and sensitive to the feelings of others, likely because of the spiritual and cultural influences of his country. Despite mystical first impressions, Cecil actually carries himself with child-like spirit and curiosity. At times he is unintentionally rude or too forward because of his inability to sense what is appropriate in the culture that he is in. He is enthusiastic about nearly everything in Japan. Perhaps because of his royal upbringing, he is used to getting what he wants and is often confused when he can't instantly have it. This is shown at one point in Amazing Aria, where he requests to purchase a shopping mall. Later in the series, he learns and matures, often demonstrating modesty and respect.
His assigned senior is Camus, who he often struggles to get along with. At times, he is frustrated when he cannot impress Camus or meet his standards.
Cecil gets along very well with Ittoki Otoya, who he feels that he can be comfortable around and depend on. While the games have made it clear that Otoya and Cecil are half brothers through their mother, the anime has not confirmed whether it wants to carry over this fact. It is hinted at in Episode 9 of Season 2 when Otoya mentions that it felt as if he had a little brother while Cecil was present.
Cecil admires and respects Ranmaru, the senior he was assigned to during the Shuffle Unit Project. He often flatters and is friendly with the upperclassman, despite Ranmaru's initally bitter demeanor, because he is inspired by his "bright soul" and respects his "strong voice". They are on good terms with one another, to the point of Ranmaru helping Cecil one on one during a recording in MUSIC 2's memory novel. Cecil also likes both Ichinose Tokiya and Jinguji Ren. [Source: wikia]
You can download the paper craft toy here: Uta no Prince-sama - Chibi Aijima Cecil Free Paper Toy Download