So, Twin Spica isn’t as heavily based in a real location as Bocchi was, but that’s not to say that there’s nothing. Mostly because manga writers sometimes like to crib their backgrounds from real photos.
Asumi’s hometown of Yuigahama is… partially fictional, but the station she’s shown leaving on page 6 is Gokurakuji Station on the Enoden line. There is a Yuigahama Station a few stations down the same line, but it’s written with different kanji - 由比ヶ浜 rather than 唯ヶ浜.
But oof, that full-armed slap that father dear delivers to his daughter on page 21. Perhaps a minor spoiler, but this ain’t the last time in this series that we’ll see a girl getting slapped across the face by their father - it’s not even the last time we’ll see it happen to Asumi - and the fact that noone even comments on it in-universe rather suggests a lot about Yaginuma-sensei’s upbringing…