Voice Actor: Chihiro Suzuki
Arima, is popular at school, he, like Yukino is intelligent, hard working and beautiful. He is also polite, and the perfect gentleman. However, Arima, also wears a mask in public. He feels that he has to be perfect for his foster parents and for himself. Why you ask? As a child, Arima was abused by his father. Later in life we was adopted, however, people said that he would become like his father, and be violent. Only his foster parents truly loved him. To repay them, and prevent himself from becoming his father he feels that he must be the perfect child. However, Yukino tells him that despite this, he must strive to be himself. The charade Arima has put up to be utterly perfect has hurt him deep down inside, and he needs to show his true self to truly live.

Despite his knowledge that he need to drop his mask Arima, perhaps subconsciously continues to use it. Personally, I think that Arima is a somewhat disturbed character. He has had to face his inner fears a number of times, each time showing us how vulnerable he really is. On at least two occasions he has shown himself capable of becomming like his parents. For example, in book 6 of the manga (or episode 17 of the anime) when Yukino shys away from his touch. Afraid of rejection Arima runs after Yukino and instead of simply talking to her when he catches up he grabs her by the arm, throws her against the wall and proceeds to shout at her, saying she can't leave him (I haven't seen the anime version, so I don't know if it's the same). Another such example occured near the end of book 7 when he was jealous of Tonami. Although Arima did not use any physical violence on him, he gave a look which could only be described as murderous and would have caused anyone to run screaming into the night.

Compared to Yukino's somewhat superficial reasons for keeping up her charade, Arima's reasons strike the heart of his emotional and possible mental well being. His mask is an attempt to protect himself from all his fears and insecurities. It will take him a much longer time to learn to show his true self.

Evidently, Arima feels very strongly for Yukino. The reason that he loves her is, as he tells Asaba, that she loves him for what he is and does not expect anything of him. Outside he appears to be confident and self-sufficient. However, he sometimes thinks that he does not know what he would do without Yukino. In fact the two afore mentioned incidends occured because he feared losing her. He has come to rely on her presence very heavily and she is easily the most important person in his life at present. He gives her some sense of belonging and self worth. After the pair become girlfriend and boyfriend he cannot see himself without her.

What other characters have to say about him:
"I really love this person. He cannot help hurting himself to protect his loved ones" - Yukino