You're my Shikon detector...

...why else would I keep you around?

Inuyasha spends a lot of the series denying that Kagome is anything to him other than a tool to reclaim the shards of the Shikon No Tama (the MacGuffin everybody in IY is chasing). Great matching background.
 

Added: 7/20/02 From: Mandarake Japan
 
You're my Shikon detector...