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.
SpoilerHe is in love with his English teacher, Kyoko.
He confesses just before her departure for her wedding.