(picture of male protagonist)
Me: Hi, my name is Hirohito Yakimoto. My aquaintances call me Hiro-kun, though if you're reading Funimation's English or French translations of this, they'll have even casual acquaintances refer to me as Yakimo, despite Japanese custom. I'm sixteen in the original Japanese version, but the American version will make everyone 3 years older to get the show past the censorers.
This is my childhood friend I've know since birth, though I won't realize until this show how attractive she is or how much she likes me.
(Picture of 1.5 meter girl with ridiculously large boobs)
Friend-chan: Hi. *bow* My name is Hoshi Sugara, though I normally wouldn't introduce myself since I'm a shy introvert who is embarrassed by the size of her boobs. I'll serve as the main love interest for Hiro-kun and, despite Japanese custom and the logic of me being introverted, will be referred to as Sugara-chan by everyone under 18.
Hiro: Despite the fact that people from all over Earth live in our colony, and the fact that computers could be used to educate people at a fraction of the cost, we go to a typical Japanese high school (college in the American version). I should also tell you that we live in the asteroid belt on the asteroid Ceres, though I'm not sure why that matters in this kind of anime.
Sugara: Because you aren't a pervert, so the shows creators needed a contrived yet somewhat original way for you to see girls in their underwear or boobs. They chose to do that by the colony and all spaceships only having one locker room which the girls and boys have to share. That means that you can walk in on me when I take a late shower or have to change clothes at an inopportune time. Also, you have to get naked to put on a space suit, apparently.
Hiro: Right. Also, they'll be other girls too, and guys. And the school will send us out on a Space ship, putting us in dangerous situations.
In case you didn't realize it, this is low casual and is meant to make fun of tv tropes, especially in anime.