Time Skip: I Had a Cute Baby with My Archenemy?

Synopsis

An 18-year-old girl time-travels 8 years into the future, only to find she is married to her childhood archenemy—and they have an adorable 4-year-old biological son! She once swore she'd rather die than marry him. Facing her cute baby and a rival-turned-perfect-husband, she assumes it’s just a loveless business marriage. That is, until she discovers his secret study filled with her high school photos and diaries. Turns out, this absurd marriage is the result of his decade-long, deeply hidden secret crush!