The series isn't deep and complex. It's just poorly paced and contains needless diversions. It was meh to begin with and totally lost the sauce half way through. The author clearly didn't have a firm idea behind and winged it, changing his mind along the way.
No isekai cheat but she is literally an adult with knowledge of the past dealing with children. I love the MC but her chad aura comes from having an adult perspective and regrets.
Even though our MC is a stereotypical wimp, he's a good straightforward guy with a lot of emotional intelligence. I love that he found out so quickly and that he's trying his best to support her.