Jon Cryer stars as Alan Harper on Two and a Half Men.  Alan is charlie's less successful younger brother.  Alan moves in with Charlie after his divorce from his first ex-wife, Judith.

Alan has weekend custody of his son, Jake, who lives with him at Charlie's.  Alan is a chiropractor, yet due to his alimony payments, is struggling and has to depend on his brother.

Alan gets married and divorced a second time to the very young and attractive, Kandi.  He's lovable and annoying at the same time.