i noticed two bugs, the first is that i must uncheck Decrypt images in tonarinyj box.
And the second bug is related to this chapter https://tonarinoyj.jp/episode/10834108156665744603 and i gess all chapter that have gif images in their pages
the .gif file should be there but your code convert that to a .png file. but when i change that extension to a .gif file it work well
in the and i think that, all your tool user, and me should thank you a lot
(sorry for my bad english)
PS: other website that are the same in the mechanism should have the same problem.