In this episode, the cast prepares for The Future of Han Na's Day race, where they'll compete according to the rules outlined in Han Na's notebook. What started as a mere guide has transformed into a rigid code, pushing the members to search desperately for it, hoping to tweak the instructions in their favor. As revisions pile up, penalties increase, fueling fiercer competition. Meanwhile, Han Na stands firm, determined to safeguard her notebook at all costs. (thetvdb.com)