Back to Eighteen, I Met My Teenage Son Instead of My Ex

At eighteen, a woman is sent back to the world she once left behind, seated again beside the school rebel she remembers as John. Only the boy in that seat is not John — it is his son, Ryder, a red-haired troublemaker who sleeps through class and skips school for the internet cafe. Years ago she had dragged a delinquent named John to success, then returned to her own world believing her task was done. Now the system has brought her back to correct the timeline, and the son has followed in his father's footsteps.

Ryder is colder and more defiant than John ever was, and he does not want her help. A slap to the back of his head earns her his fury and a hissed threat, while a forgotten phone brings a call from John himself, impatient and commanding. When she unlocks the phone with her own birthday, she learns someone still remembers her after eighteen years.

At a bakery, she finds Ryder buying a cake for his father's birthday, carefully writing a card he cannot finish. The boy is far more sensitive than he pretends. She tells him to go home and keep John company.