I have no direct knowledge of this 'yes ka no ka hanbun ka light novel'. But generally, light novels are known for their engaging stories and unique concepts. It might be centered around a complex relationship where the characters are constantly faced with choices that can be simply yes or no, or perhaps a more nuanced 'half' option. It could also be a story that plays with the idea of uncertainty and decision - making, using these concepts as a driving force for the plot.