Who Says Middle Age Isn't Wild?

After his divorce, middle-aged Su Mu accidentally activates a 'Rebellious Youth System,' gradually returning his body to 18. He helps his son out of emotional confusion and helps his daughter resolve her heartache, repairing their parent-child relationship in an unconventional way. Facing the obstacles from his ex-wife's friend group, he wins everyone's support with his wisdom and charm. In the end, Su Mu finds himself again, realizing the true meaning of life — living as your real self is far more important than living up to others' expectations.