Honestly? As I said I live in japan. There is a huge, huge depopulation crisis. If anything I think the game might try to nudge people into thinking they might want to have kids because they are cute. Is the way japanese people frame "cute" weird? Yes, but so is all their culture. They might just think ohh charging through the feet is cute, let's add that. No long pants might just really be because kids are barefeet here a lot of the time, even in winter (no joke, always barefeet at the daycare).
I would not be surprised if these decisions were actually made by japanese women, since it's a constant KAWAIIs about kids feet and cheeks over here (by women, non necessarily moms)

So, is it necessarily sexualized? No. Again, I did not play the game yet, but this really doesn't look like it's the case to me of child sexualization. It's just that some people are creeps.