Set in a prestigious all-girls high school, second-year student Yuna mysteriously gains the ability to see and speak with the ghosts of two long-dead former students -- ones that are quickly revealed to be lovers unable to move on due to the circumstances of their deaths, and regrets that bind them.
They have a plan though: they want Yuna to help make a "Yuri-topia" within the school so they can experience (see) what they didn't while alive, and thereby free themselves. Through their guidance, Yuna sets about the task of bringing couples-on-the-verge together.
Over the course of an academic year, the story of those various pairings is played out.