This app was mentioned in 3 comments, with an average of 5.33 upvotes
New Star Soccer isn't Kairosoft. If you were actually referring to a Kairosoft game, it would have been Pocket League Story or Pocket League Story 2, although you may have just gotten New Star Soccer's publisher wrong.
I think I might know what this was actually. Is it Pocket League Story?
This is the same team that developed the excellent Game Dev Story for iPhone and (later) Android. I remember playing this on my iPhone back in the early '00s.
Pocket League already exists and is a pretty good game on its own.
https://play.google.com/store/apps/details?id=net.kairosoft.android.soccer_en&hl=en