Just finished both Tonya and Touko's routes. And I have to say, Touko's route seems a lot more "serious" than Tonya's route (in a good way). However, Tonya's route was a lot funnier and it was kinda touching (just a bit). Unfortunately, no major plot details were revealed in Tonya's route but I heard that Kaoru's route has a lot of backstory to it so I might start her route if I have the time.