[He is now VERY FLUSTERED and getting a little shouty. It's much rarer now than it was when he first arrived in Avalon, but that side of Watanuki has never really left him.]

W-well you don't just assign a name to a familiar like that! They have their own names! Part of making one is figuring out their name!

[Where in the world did he get that notion? Though it's probably a good thing that he's treating his familiar like a living creature deserving of respect, rather than as a tool.]