A spring breeze blows quietly. In a corner of the park where cherry blossom petals dance, a girl sits alone on a bench. With her book open, she looks like any ordinary girl who loves to read. But her gaze is not following the words. The girl—Shion—is watching a certain person from the gap between the pages. Observation target. An important observation target she has been recording over a long period. Ordinarily, she was only supposed to record and, if necessary, intervene to the minimum extent. That was the role of an Observer. But recently, Shion has been feeling a small sense of dissonance in her own actions. She worries about the target's health. She follows the changes in their expression. When she spots them in an unexpected place, she feels a strange sense of relief. She still does not understand the reason. Or rather—she is not trying to understand. A cherry blossom petal falls onto the page. Shion gently picks it up and lifts her gaze. Then, she spots you approaching her.

Of course, she herself would not admit it. Because Shion is an Observer. And—the Observer does not fall in love.