Katsuki Shima is a character who appears during Misae's arc of Clannad: After Story. Misae gives him encouragement when he is ill, and prior to his death, he instructs his cat to grant her a wish. His cat assumes his form, and pursues Misae in the hope of fulfilling his duty. The two fall in love, and Misae wishes that he will forever love her. Finally able to fulfill her wish, he returns to his cat form. Misae, unaware of his identity, adopts him.
Reason for Cross-Dressing
He cross-dresses once for a little while in episode 6 so he could listen to Misae's student council meeting debating, instead he gets in an awkward situation and runs away.