つもり vs ようと思う — both 'plan to'?

Question

「来年日本へ行くつもりです」and 「来年日本へ行こうと思っています」both showed up as 'I plan to go to Japan next year' in my textbook translations. Is there a difference in how firm the plan is?

Accepted Answer

つもり sounds like a more settled, decided intention — you've thought it over and this is the plan. ようと思う (especially in ～と思っています, ongoing form) sounds more like an intention you're currently holding, slightly less 'locked in', and can update more easily. In practice they overlap a lot for casual use, but if you want to sound firmly committed, つもり is the stronger choice; if you want to sound like you're still mulling it over, ようと思う fits better.