Kentaro is the quintessential aristocrat, combining grace, charm, wealth, arrogance, and snobbery in equal proportions. He possesses his mother's sense of style without her sense of humility. He fancies himself a ladies' man, and the ladies do seem to fancy him as well.
Kentaro's traditional feud with Keitaro seems to have died down somewhat since his trip to Leng with Keitaro, Naru, and Nausicaa. He was on his best behavior at Marching as well. Only time will tell if this good behavior lasts.
The recent revelation of Sumire being Drake's child has forced the two of them to break up; neither of them seems very happy about this.