The good news is, there are plenty of ways to deprive him of sleep once you two get married. Ways that will give him the nine kids he wants, which will help keep him sleep deprived.
What Glomoro said. This works out perfectly if they married to each other since she can makes him have that face all the time.
You know, with the 9 kids and stuff
So the only difference between regular Shirogane and Bishirogane is a mere three hours? Not to mention he's able to overcome over a year's worth of sleep depravation over the course of one break!
I know this is overplayed for comedic value etc, but "I like you only when you are sleep deprived and on the verge of physical exhaustion" isn't exactly a comforting premise for a relationship.
@TucoBenedicto nah, she did say she prefer shirogane get enough sleep over her preference of his sleep deprived looks.
she even said she will just have to get used to his "new" appearance.