If those hours are day time hours, you can take the Airport Rapid Service train from KIX to Osaka Station. Get off here and check out everything in this complex. There are restaurants, shopping malls abound. Should you be interested in window shopping for electronics stuff, you will find couple of big store around the same neighborhood. Yodabashi Camera shop is located to the side of the station. You will be amazed what you find here. Pick up a map and tourist info at the Osaka tourist office in the station and off you go. You can kill 6 hours in the city with ease.