Donkeys in Japan

For some reason there seem to be a lot of different stores in Japan that include the word "donkey" in their name.
A few days ago I walked past "Snack Donkey", where I am guessing they sell snacks, but it was in the red light district so I didn't enter, lol. I've already walked by "Candy Box" in the red light district hoping they were selling candy. Turns out they were not..

Also there is a very strange chain restaurant here called "Bikkuri Donkey" ("Surprised Donkey") which has nothing to do with donkeys! Neither the interior nor the food is donkey related. How the heck did they come up with this name?
And by the way, Bikkuri Donkey's restaurants look friggin scary, inside and out, I have nooo idea who came up with this concept and why.

Not my pic but I know where this Bikkuri Donkey is, I've seen this scary building irl lol

In Japan there is also of course a store called Donkihote which might sound like it has the word donkey in it but  really it's from the word/name/idk anymore Don Quijote. No idea why they picked that name either..
But people usually just call the store Donki, which sounds like donkey..

Anyway, apart from the 2 mentioned above there have been so many more instances where I have seen stores with the word "donkey" in it and it is just plain weird. Why donkey? Why?