Nanako Satoko is a fictional character from the anime and visual novel series 'To Heart.' She is known for her cheerful and optimistic personality, often bringing a lively atmosphere to the group of friends. Nanako attends the same school as the protagonists and is depicted as a supportive and reliable companion. Her interactions with the main characters add lighthearted moments to the story, while her caring nature makes her a beloved member of the cast. Though not a central character, she plays an important supportive role throughout the series.