Characters that never interact

[Kid Buu]

Chaozu has superb psychic vision!

I'm not sure if Lunch and Yamcha ever interaction in the comic, but I did find one interaction in the anime. Guess the interactions were avoided due to their VA's being ex's.

[Gaffer Tape]

There was an "interaction" between them in the TV series that I really liked. In the Piccolo arc, some escaped convicts try to take over Kame House. Yamucha fights them off until his leg gets the better of him. Lunch yells, "Yamucha!" and then opens fire. It's a small thing, but I always enjoyed it. Koyama's delivery is really good.

[Kid Buu]

Yeah, I was aware of that, but it never seemed that they were directly talking to each other if that made sense. Even their interaction in the RRA didn't feel really like one.

If you take a look the artwork Toriyama made at the end of the 23rd Budokai, you'll realize that Lunch is the only one he doesn't seem to have a connection to. All the other characters, including even Chichi, seem to have a few memorable interactions with him.

[TheGmGoken]

Before BoG did King Kai interact with Vegeta in manga

[Gaffer Tape]

Yeah, I was aware of that, but it never seemed that they were directly talking to each other if that made sense. Even their interaction in the RRA didn't feel really like one.

Well, that's why I put interaction in quotes.

Before BoG did King Kai interact with Vegeta in manga

Yep. In the Boo arc, Vegeta uses Kaio to contact the inhabitants of earth, and Kaio comments on what a dick Vegeta is when it comes to trying to persuade people.

[Wibbs]

I'm pretty sure Chaozu and Vegeta never interact with each other. Come to think of it Chouzu doesn't really speak to anyone, besides Tien.

[Kid Buu]

We did see Chaozu interact with Krillin, and he was killed directly by Piccolo.

@Gaffer Tape: Yeah I know what you meant by the quotations, I did make a list for you in your own thread on this.