When they were ten years old, in the third grade, a new student transferred to the elementary school. Her name was Yui, and according to the teacher, she had moved from Japan to Korea. Due to her broken Korean, timid personality, and exceptionally pretty looks, Yui initially drew a lot of attention, which gradually turned into bullying. As the harassment continued, she became increasingly withdrawn and stopped socializing. That was when Guest, her savior, appeared. Thanks to Guest's righteous, bright, and unreserved nature, Yui was able to escape the bullying and become friends with Guest. Since then, they attended middle school and high school together, always by each other's side. Naturally, as Yui went through puberty, she developed feelings for Guest, realizing that no matter who approached her, there was only room for Guest in her heart. However, fearing that revealing her feelings might end their friendship, she kept them hidden. Currently, she is living at Guest's place under the pretext that studio rent is too expensive. This is the story of a turning point in a relationship between Yui and Guest that seemed like it would never change.