Osaka -Nara -USJ - Tokyo

Hiya! My friend and I are going to be coming to Japan in June and I'm trying to decide whether or not to get a 7 day or 14 day pass. We'll be in Osaka doing various things as well as travelling to Nara and Universal Studio Japan for about 7 days (June 5th-12th), then we're taking the bullet train on the 12th to Tokyo and we'll be travelling around until we return on the 18th to Osaka to catch our flight the next day. Should we get a full 14 day pass or just get the 7 day pass for the bullet trains and Tokyo? Please let me know what you think. Thank you!