Kitarou is a yokai boy born in a cemetery, and aside from his mostly-decayed father, the last living member of the Ghost tribe (幽霊族 yūrei zoku). He is missing his left eye, but his hair usually covers the empty socket. He fights for peace between humans and yokai, which generally involves protecting the former from the wiles of the latter. His hair is a grayish silver (except for the 2007⁄2008 incarnation of him which has brown hair. This leads to speculation that this is a complete different Kitarou). His black and yellow vest is made out of the hair of his ancestors.
Kitarou has been the icon for many things yokai in Japan since his initial appearance in the 1960’s, from statues being built of him to his own “Yokai museums,” much like how Gundam is the icon for many things military or robot Japan.
The Oldest (in terms of age not vintage) incarnation of Kitarou seen would be the Kitarou in the 2006⁄2007 Gegege no Kitarou Live Action Movie where he is a young adult with the appearance between the ages of 18-24.