one day trip from Osaka to Takayama

We stay in Osaka. Is it possibke to visit Takayama in one day? What's the best deal-- take a train, buy a tou, or should we stay overnight in Takayama?r

Possible, but you will be spending about 7 hours on board of trains:
http://www.japan-guide.com/e/e5908.html?aFROM=2157_5900

You should probably try to spend a night in Takayama instead. It takes you 3 hours and 50 minutes from Osaka to Takayama (with 3 transfers).

www.hyperdia.com

Try to reach Takayama as early as possible so you have more time to explore Takayama. You can also take Nohi bus from Osaka but longer journey.

http://www.nouhibus.co.jp/english/kyoto_osaka.html

My post about Takayama
http://whenshetravelstheworld.blogspot.sg/2013/12/japans-golden-route-...