Hachi's world is filled with dullness as he sees only blue, yellow, black, and white from his feline perspective. He feels indifferent to life, including his time spent in school where his mind often wanders. But everything changes when a new student arrives, shaking up his calm surroundings.
This newcomer is no ordinary student, but an intelligent and polite lizard named Aoi. Despite the warmer days, Aoi continues to dress abundantly, catching everyone's attention among the furry creatures. At first, Hachi pays little attention to him, but a chance encounter changes everything.
It's during this encounter that Hachi discovers Aoi's secret: his tail radiates a hue that Hachi has never seen before, something entirely mesmerizing. As he watches Aoi's brightly shining epidermis, Hachi is left in awe and yearns to witness this hidden marvel again.
Sharing their desires, Hachi's previously monochromatic life bursts into a vibrant blue. All thanks to the friendship and experiences shared with Aoi.
