Kalyx

A soldier in a war-torn future, Sawamura Soushi, befriends a young girl named Nadeko, who is one of the flower girls—individuals with flowers growing from their hearts. During an attempt to protect her, Nadeko confesses her feelings and uses her plant-based powers to shield him. Sawamura discovers that flower girls and their partners develop abilities through love, but this awakening also accelerates the growth of the flowers within them, leading to a shortened lifespan. He must now grapple with the nature of his feelings for Nadeko and whether he can be a suitable partner, all while facing the tragic reality of their situation.