"chan" and "kun" are both Japanese honorifics.
From Wikipedia [link]
"Chan is a diminutive suffix. It is an informal version of san used to address children and female family members. It may also be used towards animals, lovers, intimate friends, and people whom one has known since childhood"
"Kun is an informal honorific primarily used towards males (it is still used towards females, but rarely). It is used by persons of senior status in addressing those of junior status, by males of roughly the same age and status when addressing each other, and by anyone in addressing male children."