The reason I felt there might be jokes around this subject was initially because 'Shogun' as a word is similar to 'shotgun'.
After few moments consideration of how these two ideas might connect (remember - wherever there's a connection, there's a joke) a fairly weak joke occurred to me combining the two:
"How do you turn a Shogun into a shotgun? Give him a 'T'."
I know this is terrible and not worthy of the term 'joke', but as I've said before, I'm showing you the steps and the process and it won't all be side-splitting.
The word 'Shotgun' also has connotations with weddings - a shotgun wedding is one where the father of the bride stops the groom running away at the point of a gun.
Here's a rather contrived attempt:
There was a Shogun who wanted to arrive at his wedding in style, so he built a cannon-sized working model of a rifle and shot himself to the venue. It was known forever as 'The shotgun wedding.'
I'll continue this process soon and see if we can get even more blood out of this particular topic.
Best regards, Marc