Is there even any point to her traveling back in time to "hide"? Being immortal, she'll simply reach the time she fled from eventually and for the people there it will be like she was never gone.
Sometime's stuff is always good and I also love that art style, particularly how the eyes are drawn. I can always tell when sometime is the artist based on the eyes.
All jokes aside, wouldn't this make it worse? With Sakurako moving around so much when sleeping, I feel like that would just rob Himawari of sleep, making her even more tired in the mornings.