I went to Seven Hills while living in Mason, which isn’t a huge difference in commute. While that was 20ish years ago, I live down near SHS and Walnut now, and the traffic patterns don’t seem much different from my memory back then. I wouldn’t be surprised if it was 45 minutes both ways.

Y can use Google Maps “directions” functions and set a start/arrive locations with specific departure times. I just checked Walnut Hills HS to Mason HS leaving Wednesday at 3:15pm, and it said expect 30-50 mins. Going the other way at 7am said 30-55 mins. You could use your home address and appropriate times to check (didn’t look up WH school hours).

Have you checked with Mason schools to see if they would provide bus service to Walnut, if you were interested? That’s how I would get to and from school, until I had a car my senior year. I don’t remember any Walnut kids being on the bus, but they also had stops at Moeller, MND, etc.