A Japanese Me 262 counterpart would have to reach the B-29s

What impact could a Japanese version of the Me 262 have in the Pacific War?

It could alter the bombing of Japan only if fielded early, in useful numbers, and capable of intercepting B-29s at altitude.

The answer makes operational timing, production quantity, and altitude performance the decisive conditions. A late or tiny force would not provide meaningful defence of the home islands. The aircraft also had to climb and fight at the height used by B-29 formations; speed at a lower altitude would not solve the interception problem. If those requirements were met, the jet could force important changes in the American strategic bombing campaign over Japan.