Okay i got an idea Red bar> Mother lifeforce Blue bar>Mother Easyness The idea is to get to almost the limit of the blue bar to get sweeter koyukkuris, up and down can make the mother give birth to more koyukkuris but the red bar decreases quickly. If the red bar goes empty or the blue bar fills you lose. There are 5 levels that go up and down with the arrow keys, if you are at almost x3 on the blue bar and raise the birth level to 5 you will get top quality koyukkuris.
The text isn't in a separate file so I can't access it to edit like I do with the yukkurarium games, so You'll just have to rely on one of those cooler blokes who actually knows japanese