Living in a group home, 17-year-old Park Seon dreams of becoming an actor. But she must leave and face life alone at 18. Caught between her reality and dream, Seon hears of a ‘wish-granting underpass.’

Grandma's memorial day is difficult for Jung-hee because of the grandfather's sister. She scolds about the memorial service of grandma who committed suicide without finding her runaway husband. Somehow Jung-hee feels guilty about his disappearing. She decides to go on an adventure to solve all the secrets and end mother's adolescence.​