"What If, in World War II, Japan Got the Atomic Bomb First? "
Take the hit and then kill them all.
I'm not into alt-history, but in July, 1945, Japan's military was a very thin empty shell. It's aircraft carriers, plus or minus one merely incapacitated, were all sunk. Likewise its battleships, cruisers, and even destroyers, pretty much. Japan's longest-range bomber was the Mitsubishi G4M Betty twin engine bomber, basically a medium bomber. The Betty probably lacked the carrying capacity - weight or size - to carry an atomic bomb (IIRC, the Enola Gay and/or Bock's Car had to be modified the carry their A-bombs).
But pretending it did, then what? With its limited range, at most it might take out all or a large part of Task Force 58 (or 38, depending on who was in command). The Betty was known for being very vulnerable to damage, so its chance of getting through would not be very good.
But pretending it did, then what? B-29s from the Marianas and China would continue reducing Japan from rubble to dust. Including the Enola Gay and Bock's Car. If Okinawa was close enough, B-17s and/or B-24s could be transferred from Europe and raid Kyushu and possibly southern Honshu.
While not as capable as the CV and CVL fleet carriers, there would have been enough CVEs, DDs, and DEs, escort carriers, destroyers, and destroyer escorts, to do much of what TF58 did for a good number of months, Especially areas of Japan beyond the range of Army bombers.
Until more Essex class and the Midway class carriers came into commission along with more Iowas, and the CAs, CL, and DDs from the Atlantic formed a new fast carriers force.
And in submarines, the USN's Tench class boats were coming into commission, replacing retiring pre-Gato class boats, and maybe even bringing about the retirement of some of the Gato class, whose test depth was not as deep as the Balao and Tench class.
All in all, I think Japan getting THE BOMB would have delayed its surrender maybe a year. And ignoring Allied casualties, the extra Japanese casualties would have been hundreds of thousands, probably topping a million. "Making the Yankee"
extra "cranky" would have been way more costly than what happened in real life.