High school student Gu Yunxiao meets an elementary school girl at school.
She claims to be his wife from fifteen years in the future, and says she knows many of his secrets.
The still-naive Gu Yunxiao smiles shyly. "I believe you."
Su Qingxi, from the year 2033, told a colossal lie. She deceived Gu Yunxiao, her sworn enemy fifteen years in the future, by claiming to be his future wife.
She keeps lying and talking her way into inventing a whole future, all while preparing to kill him at any moment.
Only later does Su Qingxi realize that she'd drawn a grand promise for Gu Yunxiao, the great villain who was nearly starving to death, and had accidentally fed him until he was full.
When Gu Yunxiao learns that the promise he fed on was fake, he says:
Either destroy the world and take Su Qingxi down with him, or she can make him a real promise this time.
