she is the biography teacher, she has a microscope.
if she know the sperm does not have the y the xy pair, why don't she ask him to masterbate.
really, there is a lot of plot hole in this mess.
the image that the author is trying to create is really messy and fuck up. or may be just my mind ??
The expression is kind of like when it should be best to do it by image, you can't find a right image so you just describe it by the best of your limited vocabulary.
it's actually a very common plot twist in dramas these days. The strongest at the moment only need like on more flick to finish it for good then using talk no jutsu or fake slow-mo, giving the chance for the opponent to get to the people who were suppose to run away because of their uselessness...