Well, you could say 'a protracted account' or 'a drawn-out story'. These convey a similar meaning to 'a long story'.
Some synonyms could be 'a lengthy tale' or 'an extended narrative'.
A long tale. For example, 'The Odyssey' by Homer is a long tale full of adventures.
A long tale. For example, when we talk about the legend of King Arthur, it is like a long tale filled with adventures, romances and heroic deeds.
Epic, saga, tale. These words can be used in place of 'long story' in many cases. For example, instead of saying 'Here is a long story', you could say 'Here is an epic' or 'Here is a saga'.
It could be 'it's a protracted account'.
There are several synonyms, like 'it's a complex matter' or 'it's a convoluted tale'.
Narrative. A narrative can be a fictional or non - fictional account of events, like a historical narrative that tells about past events in a sequential way. It often has a beginning, middle and end, just like a story. It can be used to convey a message, describe a situation or share an experience.
Tale. For example, 'The Little Red Riding Hood' is a well - known tale. It has the same meaning as story, often used to refer to a fictional narrative.
Within the story, inside the story, as told in the story.
A tale. For example, 'The Little Red Riding Hood' is a well - known tale which is also a story.