Botan Ichige enters St. Asmaria All-Girls School alongside her friend Shinobu Itoko, aiming to fulfill her fantasy of a tea party with angelic maidens. Their world shifts when a mysterious angel, Un, offers them a peculiar halo to consume. This act leads to an unexpected outcome as Botan and Shinobu produce vibrant mushroom-like entities. Despite initial discomfort, Botan finds solace in Un's promise that her desires can be realized by laying a multitude of 'eggs.' Encouraged by this enigmatic challenge, Botan embarks on a journey to make her whimsical dream a reality, setting the stage for a unique and whimsical adventure.