I never liked this thing where the child of the main character ""is hinted"" to experience the same thing as their parents. Really weak. Maybe I'm a bit biased because I was and still am team Onodera.
Nah this the best ending for her, to finally found someone who really love and cared for her. That's why she settled down and had a child with him. It's been 10 years for them, I'm glad Kosaki happily moved on, unlike her fans 🤭