No. It's not a common phrase at all. I've never come across it in normal English usage. It seems like an odd combination of a possible name 'finn' and the very common 'end of story' which is often used to close a discussion or emphasize finality.
If we break it down, 'fin' often relates to an end or extremity. However, 'finn' as a whole is rather unclear without context. It could potentially be a code or just a random combination of words that someone thought made sense. If it's a new or made - up term, it might only have meaning within a very specific context or conversation. The 'end of story' part seems to emphasize finality, but what that finality pertains to with 'finn' is a mystery.
I'm not entirely sure what 'aj finn end of story' specifically means without more context. It could be a name 'aj finn' and 'end of story' might be used to emphasize finality or that there's no more to be said about aj finn.
Well, 'aj finn' could be a person's name, perhaps an author or a character. And 'end of story' is a common phrase used to indicate that there's nothing more to say about a matter. So it could be that when it comes to aj finn, there's a situation or a narrative that has come to an end and that's all there is to it.
Well, 'a j finn' could be a person's name, perhaps an author or a character. 'End of story' is a common phrase that means there's nothing more to add or discuss. So it might be saying that with regard to this 'a j finn', that's all there is to it.