Leon: Between you and Aisha, it seems this is a planet of young geniuses.
Aisha: Oh, no, Leon. I may be a special case, but Leelong here is a lot older than she looks. You ought to be calling her "Oba-san". O-ba-sa-n.
Leelong: O-oba!? Say, Leon, I take it you're not too familiar with Aisha. Don't worry too much. Not to say all the nutrition she got just went to her breasts, but she seems to speak a language unknown to mankind at times.
Aisha: Na!? Oh, no, you don't know what you're saying! Honestly, oba-san! Ahahahaha!
Leelong: Oh, do you not get the joke? You useless breast woman! Hahahahaha!
On the subject of oba-sans, both Sara and Mao do not take kindly to being referred to as "grandmother" (obaa-chan) by Sheryl when they first meet. They figure out the situation quickly enough, but both tell Sheryl to cut it out with the obaa-chan title.
When Mylene joins up with the group, she gets a replica of her mother's custom VF-1J. She laments that while the plane is cool and all, it doesn't have the bass guitar control interface she's used to. Leon and Alto immediately Lampshade what an incredibly bizarre control scheme that is.
When Mao meets Sheryl, she practically suffers a Squee overload:
Mao: Ooooh! With a granddaughter this beautiful, I've got to have married someone really handsome! It's Shin, isn't it? Isn't it!?
Sara: Wha? Shin? Mao, listen...!
Sheryl: Ah... sorry, but that is rather private information, so I'm afraid I don't know much about my ancestors.
Sheryl: Shin would be the same person you two were in a Love Triangle with?
Sara: She-Sheryl! What are you saying! For a Mayan shaman like myself to have that kind of relationship with Shin...! In the first place, how would you know of that?
Sheryl: In this world of the future, a movie was made. A movie about the Mayan Bird, the legendary pilot Shin Kudo, and Sara and Mao, the two girls who fell in love with him.
Mao: A movie!? About us? Hey, who played me? Was it someone cute?
Mao: Sooooo cuuuttte! So this is the image people will have of me in the future? Awesome!
Whenever Aisha is feeling particularly attached to Mina, she calls Mina her "daughter" and occasionally refers to Leon as "Papa". Leon is not amused by this. Then Mina decides to tease them about this:
Mina: I'll do my best then! Aisha-mama! Leon-papa!
Leon and Aisha: Huh!?
When Brera joins the group, he jokingly(?) says Alto is no longer necessary since he is here now to protect Ranka and Sheryl. Alto butts heads with him over this until the girls tell them to cut it out. In the background, Guld chuckles. Brera asks what's with that, and Guld responds that he's just feeling somewhat nostalgic (referencing his Vitriolic Best Buds relationship with Isamu, no doubt).
Guld and Isamu meet in person and immediately begin arguing with one another. Leon and Mina are a little worried, but Myung tells them not to worry. A few minutes of dialogue later, the two are still arguing (with a Call Back to their childish argument in Plus):
Mina: Umm... are those two really okay?
Myung: Leave those two idiots alone. Shall we get going?