Sylvain is very nice. He can overreact at times and is an otaku. When he traveled to Japan, he was introduced to samurai movies, anime, and manga. After that, he based his life off of them. When Yuuta first arrived to the academy, Sylvain noticed the bunny charm on his suitcase and was drawn in. Sylvain is the drummer of the band "Red Prince". Not much is really known about Sylvain's past. It is mentioned that Sylvain's family had to move from place to place a lot due to his parents' work. In addition, in episode four it seems as if he and his mother had a dramatic past. When a teenager, Sylvain was recruited by army forces and was taught to fight and shoot. He is still ordered to carry on investigations while studying at St. Alphonso Academy but Sylvain himself doesn't enjoy it. Taking this fact into consideration it seems he works for the army in order to pay for his own or his family's past wrongdoings.