So I know this is probably a late comment all things considered but up to this point we don't know what Tsukasa did before she married Nasa or did I just miss where it was mentioned?
@-Aincrad- This is a gag manga... you aren't meant to take this that seriously.
Remember, this is a place where a tiger biting a person's head won't do real damage... a world where people can have life ending falls and survive... take any danger and threat with a huge grain of salt...
You are taking this more seriously than you should...
The New episode of the anime made me realize something.
Kaguya is Chitose's older sister and Tokiko's granddaughter. That's why they have a moon stone at the mansion in the First chapters. Chitose says the moon stone is something special do her nee-sama because it conforts her. The only girl who really cares about going to the moon is Kaguya. Also, Kaguya is Very small and knows all the basics of programing, Tokiko was the minister of education and know how to program in C. I think Chitose has two older sisters, a blood one (Kaguya) and the one who she deply admires (Tsukasa). At last, but not least, Chitose and Kaguya look alike, their hair is kinda similar.