I remember in third grade, one of my classmates became an aunt, so only the part about lack of IPS cells in yuri resulting in pregnancy is crazy. (Her older sister was like 12 years older and had a different father, though...)
Also, considering what she asks of her other sister, that makes her cluelessness regarding sex even more alarming. Was she trying to get pregnant before?
Aha!Ah!It's your fault, sis!Let's stop already! This is too weird!See? You're soaking wet now.As a middle schooler!Just bear with it.Don't touch there!You're just too sensitive.M-Miki-neesan's gonna get pregnant...!!That means I'll have to use my savings and New Year's money to buy a crib for them!!Miki-neesan and Yoh-neesan...I'm gonna become an auntie!It got wet, after all!are mating in the bath!!I said it's fine!