In Los Angeles, the young Jenny has a nice childhood with her Korean parents Joanne and David Kim. However, after the divorce of her parents, the judge gives her custody to her selfish mother that neglects Jenny while the disappointed David returns to Seoul. Six years later, Jenny is a troubled and reckless teenager expelled from the public school that has easy sex and uses drugs and booze, and her best friend is the orphan drug dealer Becky. The lawyer Elliot Krasner decides to call his former friend David to tell him about the self-destructive behavior of Jenny, and David returns to Los Angeles. He brings Jenny to live with him and support her, but the lack of emotional structure of Jenny imposes tough difficulties for their relationship.

Three young boys, Rocky, Colt and Tum Tum together with their neighbor girl, computer whiz Amanda are visiting Mega Mountain amusement park when it is invaded by an army of ninjas led by evil Medusa, who wants to take over the park and hold the owners for ransom. Kids and retired TV star Dave Dragon, who made his farewell appearance at the park at the time the ninjas appeared, have to break Medusa's vicious plans.