Sae Nagumo  

Sacchan, 名雲 紗絵

Nagumo Sae is a young girl who serves as the main male character's love interest. She experiences short-term amnesia, which means that she forgets things that have occurred since she woke up. Initially, she tries to conceal this condition in order to be perceived as normal and healthy. To aid her memory, Sae carries a book called "Book of Memories." In the past, Nagumo met Sacchan before he moved away with his family, whom he had forgotten. Despite their separation, Sae waited for him in the park until he returned. She is accompanied by a nurse who serves as both a friend and her guardian. Although the nurse can be challenging to deal with at first, she ultimately sees Sae as a good person.