桜田 ジュン

Jun is originally a junior high school student in the second year, but after cracking under the pressure during the accident of school festival, he lives a hermit's existence in his room and does not go to school anymore. He suffers from what is known as tōkō kyohi, or a refusal to go to school, as well as a hikikomori, the phenomenon of isolating oneself from society. He spends a lot of time in front of his computer, and has a hobby of ordering things from the Internet — mostly fake magical or occultic implements— and then returning them before he has to pay, for the thrill of receiving something ridiculously stupid. 

When he comes into possession of Shinku and winds her up, he is unwittingly and unwillingly caught in the crossfire of the Alice Game — Shinku declares him to be her "servant" and demands that he obey her at all times. Jun is extremely skilled at crafts and at sewing. Although he is arrogant, and occasionally cold and rude, he cares for others but typically refuses to let his feelings show. He is especially friendly with Hinaichigo, and at times, blushes around Shinku, which portrays that he cares deeply for her.

Later on in the series Jun's personality changes, thanks to the Rozen Maidens who have taken up residence in the Sakurada home. No longer afraid of his classmates or of going out in public, he goes to the library frequently to catch up with his school studies and is more sociable and kind. He even becomes friends with Tomoe, Hinaichigo's former medium, as she helps him catch up with his studies./
Jun also helps Suiseiseki (after becoming her medium) try to convince the other Rozen Maidens that the Alice Game was a futile endeavor. He strongly believes that because Shinku and the other Rozen Maidens are sisters, they should not fight or keep secrets from one other.

Shinku states that when Jun sews, it is like watching magic. Jun is the only or one of the few people in the world who can bring a doll's 'soul' back, doing so in the first volume with an old doll. Jun is able to be the master of two dolls (Shinku and Suiseiseki) at once and have them take his energy in battle with little problem. This is unusual because most people have a hard time with just one doll taking their energy. The reason why he is able to do this is unknown and might have something to do with the fact he is similar to Rozen. 

Edited from url=http://en.wikipedia.org/wiki/List_of_Rozen_Maiden_characters#Jun_Sakurada.