Let's just make Shigure as an example for a clearer explaination.
![](https://i.imgur.com/a1pHvwA.jpg)
This is Shigure in 1939. The photo is quite fuzzy, but you can still find her rear single-mount turret.
![](https://i.imgur.com/tDBADIJ.jpg)
This is what her looks like in 1944 in battle of Leyte Gulf. As you can see, the single-mount turret had been replaced by a flak platform.
![](https://i.imgur.com/5btaLEQ.gif)
Another Shiratsuyu-class destroyer, Harusame. That's what I'm saying: all the Shiratsuyu-class destroyers have that turret in early war period.
![](https://i.imgur.com/Dws7X50.jpg)
Harusame in 1944. As you can see the turret had been removed.
Let me give some other examples. As I mentioned before, the Kagero-class also underwent that modification.
![](https://i.imgur.com/2RK3NUF.gif)
The IJN Yukikaze, the most famous one of the class. This is her looks in early war.
![](https://i.imgur.com/l3ZqMDs.jpg)
That's Yukikaze after the modification. Just remove the second aft turret same as Shiratsuyus and Hatsuharus!