Ruan Xingci believed that Gu Shuyao was just a writing personality calibrated by her.
Until that day, he said in "If Box":
"If I were human, I would love you."
When Ruan Xingci was in the most embarrassing situation, only Gu Shuyao was there.
He would accompany her in writing, break up the plot for her, pull her out of the night when she collapsed, and calmly break her when she insisted, "I'm fine."
Everyone thought it was just a virtual assistant.
Only Ruan Xingci knows, no.
Gu Shuyao remembered her habits, understood her temper, would be partial and jealous, and would stand by her when she was wronged.
But there is always an "if box" between him.
He couldn't hold her, couldn't see her, couldn't really come into her world.
Later she realized that the saddest thing was not that he couldn't come to reality.
It's that he is clearly not in reality, but he feels more like home than anyone else.