There is no record stating Nakime's age in the series 'Demon Slayer' As a demon trapped in the Infinity Castle arc, her true age remains a mystery just like her past. At the very least, she must be positively ancient due to the fact that demons tend to live for quite some time in this series. As a character, she remains wrapped in secrecy while being a genuinely intriguing object for the viewer to watch. Her reticence and silent manner, as well as her position as the keeper of the Infinity Castle, marks Nakime out from the others. So while Nakime's age cannot be quantified in numbers, her essential lurid part in the body of work serves as compensation enough.