Trip Question

Hello! 3 friends and I will be going to Japan in late oct 26 for 9 days we have rough outline of what we want to do and where we are going but we want an outside opinion on what to do on the way to Osaka.

We plan to arrive in Narita airport then stay the night in Tokyo. Then the next day we were thinking of taking the Shinkansen to Fukui to the dinosaur museum. Same day we will then continue to Osaka where we will stay the remainder of the trip. Then last day we leave go back to Narita airport since we have a late flight back.

Would it be better to make Fukui a day trip after reaching Osaka or keep it the same as a on the way stop?