A year of chasing one stage, and the Bloom Garden Party finally arrives. What hits isn't the concert itself, it's watching Kaho and the others understand that this moment was always about the people standing next to them, not the applause waiting at the end. The 103rd-year students get one last day as students together, and the movie doesn't waste a second pretending that doesn't matter. This is what school idols actually means: the promise you make with people you're about to leave behind.

For a whole year, Kaho and her friends in the Hasunosora school idol club have been working toward one goal: the Bloom Garden Party, a stage where they hope to finally bloom. The day has come to fulfill a promise they made with the graduates. It is also the last day the 103rd-year students, about to graduate, can spend with their friends as Hasunosora students. Even so, the girls pour everything into their youth. This 3DCG music and slice of life film centers on girls striving to bloom and on dreams they realize together.