Choosing the moon more times than choosing the sun will trigger a dark ending, and each ending corresponds to the story of a different man, as shown below.
Chapter 1: Light-Xiao Yi, Darkness-Lu Chen.
Chapter 2: Light-Zisley, Darkness-Lu Chen Android.
Chapter III: Light-Xiao Yi, Darkness-Lu Chen.
Chapter four: Ming-Xiao Yi, Dark-Qi Li Si.
Chapter 5: Light-Zisley, Darkness-Lu Chen.
Chapter 6: Light-Sue, Darkness-Xiao Yi.
If you prefer Xiao Yi, you can choose the option of the sun; If you prefer Lu Chen, you can choose the moon. I don't know who I like, because I can reset the plot with retrospective props later, and then I can choose another option.
In short, this option is actually not important, because you have to trace the ripple to see another ending. No matter how you choose now, it can only lead to an ending, and you can only choose between two men.