If you read Searching or Evolve on FF.Net, you'll know what I'm talking about.

Genji-->Grimmjow-->Ginjo
Ukita-->Ulquiorra-->Uriya
Akari-->Orihime-->Himeko

Akari called Genji Gen-chan, and he'd pinch her cheek. I don't remember what Ukita called Genji, but he called Akari Hime-sama, and then Hime.

Orihime called Grimmjow Grimmy, and well you know. Ulquiorra threatens him with a sword (again). He calls Orihime Hime as soon as he got his memory back!

Himeko called Ginjo Gin-chan, and the same thing happens. Uriya threatens Ginjo with a Quincy's pride and joy! Himeko is still called Hime!