Nara is a fine side trip from Kyoto. Lots of ancient temples in a relatively compact historic district, easily covered in a day of walking around.

Although I had planned to take the shinkansen from Osaka to Kyoto and, after a four-day visit to Kyoto, on to Tokyo, participants in this forum convinced me that it was unnecessary. They were right. Ordinary trains cover Kyoto-Osaka in less than 30 minutes with as few as two stops.

If you stay in Osaka, I'd recommend Ron steakhouse. Best. Piece. Of. Beef. Ever. Anywhere.