The 'Taebyung and Reader Moan Story' is rather ambiguous without further details. It could be a work of fan - fiction, for example. If Taebyung is a character, the story might revolve around his interactions with the reader. The'moan' aspect could be related to a reaction within the story, like a reaction to a discovery, a moment of shock, or a deep emotional response, but this is all speculation.
Since I don't have prior knowledge of a particular 'Taebyung and Reader Moan Story', it could potentially be a story that delves into the deep connection between Taebyung and the reader. Maybe they go through various trials and tribulations together, and the'moan' could symbolize the pain or pleasure of their experiences, but without more context it's hard to say for sure.