Board Thread:Theories and Speculation/@comment-45444155-20200728155230/@comment-3523655-20200801191920

ReweR 1331 wrote: As we can see from further chapters of the series, Naruto has been using Sage Mode for more than 5 minutes... in short, it's more of a conditionality that has been forgotten...

That's because Naruto's gotten used to using it. But you look at the first time we see Hashirama use Sage Mode, he needs to focus for a bit and THEN he gets it.

The point is: Sage Mode is finite. At some point, the form runs out. But with Jugo's cells, and consequentially, Sage Transformation, Kabuto was able to maintain Sage Mode indefinitely.