Kinning is when you relate to a character, in basic terms. However, it goes deeper than that. You feel as though you have a connection TO the character, as in, you feel as though YOU ARE the character. Characters you kin don't have to be your favorites, they simply have a connection to you and ARE you, per se.
The urban dictionary describes the meaning of kin as “a character (or characters, you can have more than one kin) you associate/identify with. kins are to help you express yourself, comfort you etc.” Many TikTok users are making videos about their anime kins and some people even have multiple.
your relativesYour kin are your relatives.
Source: TikTok. That said, kin is a word used to show love and admiration to characters in the TikTok world, according to Height Zone. So, the best way to think of kin is as the word like. If you're a fan of a specific anime character, you would say that you kin them.