Shuu Maiko

Although Shuu appears to be playful he is actually very sensitive. He was the first one who realized that Chitoge and Ichijou were not actually dating. Also he was the only one who seemed to realize that Tsugumi was a girl though he hid the thought and decided to play along just for his own amusement. Also it should be noted that Shuu is the kind of person that would do almost anything for a laugh. Best friend of Raku Ichijou. Source: