Friends and friendship.
Friendship can be thought of in many layers. First layer is general, then second is special layer.
In general you come to how friendship is formed. shared interests, same environmental profile, similar age group, loyalty (often mistaken).
When you come to special groups, you get friendship between disparate groups.
May be grandchild and grandfather, office colleagues, even travelers. Here, the loyalty component is not that much. Other than that, you have shared interests as more predominant.
friendships may lead to deeper levels such as liking, love, may be also obsession.
Best friendship will be more of a mentor, advisor, protector against wrongdoing. And loyalty to morality rather than friendship.
