Misako Watanabe is a student drawn into investigating the baffling disappearance of her classmate, Ryouko Miyazaki. She pursues this mystery alongside Kenichi Akizuki. Their investigation hinges on a crucial clue left behind, signed by Koushin Okazaki—a name belonging to a deceased classmate whose suicide was an attempt to preserve his youth, echoing Peter Pan mythology. This enigmatic clue forms the core context for Misako's involvement.

As a central figure within the single-episode OVA narrative, Misako actively participates in resolving the disappearance through collaborative problem-solving. The story confines itself solely to her role within this specific incident. It provides no details about her personal history, family, life beyond the investigation, character design, personality traits, relationships outside the core plot, or any development occurring before or after these events. Official media contains no further appearances or expansions of her character beyond this storyline.