The story of the movie is somewhat based on the plot of the most recent game, "Sakura Wars 3," released back in March this year. While the game features Lieutenant Ohgami, the main character who takes off for Paris, narrates one side of the story, the movie unveils the secrets behind Hanagumi. Ohgami leaves for Paris, consequently leaving Hanagumi without a leader; thus a new character will be introduced here. To be replaced with Lieutenant Ohgami is the former leader of Hoshigumi, Rachette Artile - a rationalistic and distinct individual, who brings about serious problems to Hanagumi. The members are now in discord with Rachette. Meanwhile, Teikoku Kagekidan was being threatened by some irrelevant demons and a new type of anti-kouma mechas, (brought by an american company) appears and tries to replace the koubu-kai. Having made repeated mistakes due to the absence of Ohgami, Hanagumi is now faced with an unprecedented danger, while the abolishment of Teikoku Kagekidan Hanagumi is being schemed.
大一新生杜苍碧在一次偶然的机会来到“Rainy Color”咖啡店工作。在那里,他遇到了冷酷英俊的岩濑清一、匆匆忙忙的樱木龙田、温柔女性的“Rainy color”刺客店主高贺白也,以及过度自由奔放的店主田木宏。