Lelouch and Mao's friendship in this series. The fact that Mao received a terrible fate in the original series and the only person he considered a friend was C.C., who abandoned him, didn't hurt.
Lelouch: Oh, enough of this idle chit-chat, what's your stake in this Mao? Why are you here?
Mao: Ah, its a really weird story man, I don't even think you would believe it. But put it very, very simply, that green-haired girl you're always with, I think she's a psycho.
Lelouch: Mao, will you be my best friend?
Lelouch: We have so much in common.
Mao: You know its funny, I thought today was going to suck, but turns out I'm going to find the girl I've been looking for forever, and I got a new best friend.
Lelouch: *looks up and stares out the window*
(Cut to an unstable Shirley pointing a gun at both of them)
- Turns out Mao wasn't lying either, when Lelouch gets shot Mao really is concerned for his safety:
Mao: Lelouch buddy, you okay?
Lelouch: I feel like sunshine right now.