Sonosuke is stated to be a "silent type", who avoids talking to others, the only exception being his romantic partners. He is incredibly loyal and very protective of them, often deciding to rest his head on their lap. Though otherwise calm and serious, the way he eats candy is rather comical. He loves sweets. Once Sonosuke's trust is broken, it is very difficult to gain it back, as he believes "once a traitor, always a traitor". He’s tall with short blonde hair and red eyes.