To be friends, because Yamamoto thinks he is cool, and Gokudera sure does too. And the boys collect friends; it's what Tsuna would do so, of course, his Guardians are going to do the same.

Yamamoto grins, must be hard being a King if a simple invite causes this. He'll have to make an effort to come to see King regularly, so he doesn't get lonely!

"Really! OH, MAN, You're the best! When are you available? I know being a King, you must be busy, so we'll be ready whenever you are!"