Feeling heartbroken after her crush was caught kissing his girlfriend, Rika Hikaru agrees to go with her parents to Frankfurt’s historic Römerberg. Walking around the town hall square, she lets her feet lead her to a dimly lit alley between stores, where she hears cheerful songs coming from the end of the alley. Drawn by the warm glow of lanterns and the lively laughter, she finds herself meeting charming strangers and a perfect party, which is just a little too perfect.