heh the mailmans dropping off lees mail and he just goes beserk.

Mailman: Well hello lee, here's your mail

Lee: I must protect.....

Mailman: protect who from what?

Lee: Gai sensai please acknowledge this.

Mailman: Huh? Whois Gai

mAilman: ahhh Wtf let me down.... *splat*

I'm sure Gai can do it how else could he teach it. Also we know Kakashi can open 1 gate.