Anyway, on a whim, I decided to transcribe/translate/summarize what I consider the most interesting parts. I'm obviously not writing every word of what they're saying because they all talk really fast, keep talking over each other, etc. But I tried getting the important parts of the conversations.
If anyone wants to listen for themselves, here's a download. The part I'm transcribing/translating/summarizing starts at 15:25 and ends around 31 minutes in.
[Skipping to the point where they answer questions that people send in-
First question is from someone who went to the Gainax event, asking about the animals that Lord Genome created. Among other things, Nakajima says that they came up with the names of the animals first, and the designs were based off that.
From this they go on to talk about the event itself, because Marina and Kakihara had no idea about it and are a bit miffed that they weren't invited. Nakajima describes it, how it was 3 hours long, over 300 people came, and that the place was so full that people could only get in via lottery, and that it was right after the end of the anime broadcast, so naturally people had a lot of questions.]
Kakihara: What kind of questions?
Nakajima: Like for example...
Kakihara: Like, how old is Viral?
Nakajima: 830 years old.
(sounds of disbelief)
Kakihara: What are you basing that on?!
Nakajima: Oh? I decided on it!
Marina: That's right, if Nakajima-san says it, it becomes official!
Nakajima: I know, that's why I've really been reflecting on it, and I'm sure everyone knows, but I talk really instinctively, so if someone asks me something, I answer right away, right then. Everyone knows that half of it is lies, so I've just been going along with it, but on the other hand, there are also people who are listening seriously, so when I was asked seriously and I replied that he's 830 years old...they had such a sad face. I reflected on that, like "I see, if I say it, then it becomes official!" So I've been reflecting on it a little.
Kakihara: You said you're sure everyone knows, that you reply to something right away, but the thing is everyone doesn't know.
Marina: That's right! So if you ask, you'll get answers right away, but on the other hand...
Nakajima: Right, there are a lot of lies.
[Nakajima talks about how they had meetings to decide on the story, where they would just throw all sorts of ideas out, and he thinks that you can come up with better things that way.]
Nakajima: So like now, I would just reply on the spot, but it's the most fun that way. Afterwards, if someone says "That's messed up!", then I'll think of how to get that to make sense. Because at the very beginning, when I asked the director what he wanted to do with the 26 episodes, he only replied with one phrase: "You're the one who has to go beyond the impossible and kick reason to the curb!" So from there I tried thinking of various things, like "what about Spiral power"...
Marina: So Nakajima-san came up with all of that...
Kakihara: That's cool, the way you do things, how you take stuff you just throw out and tie it all together...
Nakajima: It's fun, and gives us a lot of space, right? If we go by reason, I think there's a limit to that, in how we create things. So even if it's crazy, as long as it's interesting, then we can take that and just keep going forward...that's just more fun, and that's Gurren Lagann so...
Marina: Really...it's like a real Gurren Brigade.
[Talk about Iwasaki for a while, referring to a previous radio broadcast, and how he made the music. Apparently Iwasaki doesn't like robots but really loves Gurren Lagann.
Kakihara brings up what Simon was doing during the 7 year time skip.]
Nakajima: Simon spent one year making the Kamina statue.
Marina & Kakihara: Ehhhhhh?!
Kakihara: What was he doing as Commander-in-chief?!
Marina: What was that, his hobby?
Nakajima: No, but you know, he became the Commander-in-chief, but Simon is really only good at digging, right? Actually, it was Rossiu-kun who kept growing, became smart, and Rossiu-kun and his team took care of everything. So Simon would stand at the top of Teppelin, look out the window, and mutter, "What should I do?" So then from beside him, Nia would say "Please make a statue of Aniki-san."
Marina: Nia said that?!
Nakajima: Nia said that.
Marina & Kakihara: Ehh?!
Kakihara: Are you sure you're not just coming up with all this in your head right now?
Nakajima: Actually, this is from the beginning of the 3rd novel that I'm writing right now.
Kakihara: Ohhh, I see.
Nakajima: I came up with it the day before yesterday.
Kakihara: That's fast! So this might not actually be in it?
Nakajima: It's coming out next year.
Kakihara: But since you've said it here, it might not actually...
Nakajima: Yeah, that's right, this scene might not actually be in it, that's true. But for me it's official. At least, I'm doing it with that in mind. So in my head, that's what happened. Simon was probably in that sort of position. When you get right down to it, he can't do that sort of thing, and that misfortune is what becomes the disaster in the 3rd arc... But there was also one more reason for that. When Nia saw that Simon didn't believe in himself and she found him making Aniki-san's statues, she said "I can see how much you loved Aniki-san by looking at these statues," right? So going from that, Nia said "Let's show everyone how great Aniki-san was. If we put the statue you made in the middle of Kamina City, it should come across to everyone. So please make that statue," is how Nia said it.
Marina: After hearing that, now when I think of Kamina's statue getting destroyed later on, that's really sad.
Nakajima: I know, it's sad, isn't it?
Kakihara: That statue, it's like a moment where there's a big change in history.
Marina: And you thought of this the day before yesterday?
Kakihara: It sounds really simple, but it's deep!
[Question 2: "If you were to write about one of the minor characters as a gaiden, which character would that be?" Nakajima replies immediately.]
Nakajima: That would be Attenborough.
Marina & Kakihara: That was fast!
Kakihara: And I bet that was on the spot too.
Nakajima: Attenborough has a lot of siblings.
Kakihara: No way! Really?
Nakajima: Yes, really!
Marina: I bet he has like ten.
Nakajima: There are around ten of them, yes.
Marina: And they're all alike?
Nakajima: They're all alike.
Marina: There are girls too?
Nakajima: There are girls.
Kakihara: They were all born in a hurry?
Nakajima: They were, and they all eat fast, so there's never enough food. So that's why, the Attenborough family that's so poor, but they keep working hard to survive, I thought that would be a good story.
Kakihara: And why he was the only one to join the Gurren Brigade too?
Nakajima: Actually, it looks that way, but really it's three of them taking turns.
Kakihara: Like when he succeeds, and when he misses...
Nakajima: Right, right.
Nakajima: No, that's a lie.
Kakihara: See, there we go, jeez...
Nakajima: I really just came up with that this moment.
Kakihara: Really?! So about wanting to write a gaiden, was that a lie too?
Nakajima: Well, I just thought who would be the most interesting character to write about...
Marina: Yeah, Attenborough is such a great character...
Nakajima: With Attenborough, I wrote so many scenes for him, but they were always the first to get cut.
Marina: That's so mean!
Nakajima: He had so many scenes!
Kakihara: Then how about Tetsukan, why is he always so sleepy?
[Summarizing that bit: Tetsukan is always so busy that he rarely has any time to sleep. So he's actually a very hard worker, and that's why he's constantly sleepy. And that's how Cibera has a thing for him. Nakajima points out how they were sleeping together in the alternate universe, and that Cibera is the only one who really understands just how hardworking he is.]
Marina: Speaking of gaidens, you could really do a lot of side stories for Gurren Lagann. They didn't appear that often, but there were a lot of great characters.
[Nakajima talks about the side story he wrote about Bachoun, how he survived, and his younger brother Kouza who appeared in the series (the Gulaparl pilot who got shot down in the first Mugan attack).]
Nakajima: And well, more seriously, I'd like to write about Viral.
Kakihara: Ah, you know that scene in episode 26, with his dream, how you came up with that and stuff...you could make a story out of that. Like how he came to want a wife and child...
Marina: Honestly, I think you could make 26 episodes just with stories about Viral.
Nakajima: That's right.
Kakihara: Like Gurren Lagann from Viral's point of view...
Nakajima: Right, right.
Kakihara: That sounds fun...
Marina: We'd love to see that animated. I guess it'd have to be a movie!
Kakihara: A movie, huh?
Nakajima: A movie, huh, Manabe-san?
Manabe: That's what they're saying, but...what do you think, script writer?
Nakajima: I'm busy.
Nakajima: So it wouldn't be possible.
Marina: It wouldn't happen unless Nakajima-san gives his okay!
Manabe & Nakajima: That's how it is.
Marina: So until you're done with what you're writing now. When would that be?
Nakajima: That would be next year.
Fzghiuaxzg, now I'm listening to episode 38, which has Nia's VA and Nakajima as guests, and Fukui-san is so adorable. ♥