'ships' is short for imagined relationships between specific anime/comic characters. Sometimes the ships are more like friendships and sometimes more like marriages. Sometimes its a male and female, sometimes two females, and sometimes two males.
There are entire fan clubs organized around specific ships. Most of these clubs are populated by very young children who write fan fiction, draw pictures of their ships, etc.
All very, very creepy.
You’re lucky to have gone this long without knowing about them.
I discovered shippers back in college when I saw a blurb somewhere about Kirk and Spock (early 70’s when Star Trek reruns were starting to gather steam with the fanzines).
Eewww!
Sounds a lot like Furries...................