LIKE A BIG SISTER
iirc there was a timeskip already in her middle school along with that boy in the park.With the main series ending, I wonder if this chapter is the prelude to the spinoff ending as well. I would be fine with the final chapter of Chi going to elementary school, followed by a panel or two a of time skip showing her in middle school, emulating her parents in the main series.
This is Takagi's usual teasing, but Japan is so safe that children are encouraged to go to and back from school by themselves at a young age to learn to become independent. Of course it doesn't mean she won't be able to take Chii to school, Takagi is just teasing her.WHY won't she be able to see off or pick her up??
That means we're growing old....They grow up so fast...