travelling from Osaka to Toyko one way ticket

Hi there!

Yes, if you wish you can purchase tickets at Narita airport to take you from Narita to Osaka station by visiting the JR ticket office and paying with cash or credit. Here's a sample itinerary for you. If you are going one way however, you may also want to look into an internal transfer flight with the airline carrier you arrive with as it may be cheaper and faster to do that.

Hope this helps!