The sextuplets attend a high school class reunion. There, they see all their former classmates who have become "proper" adults with company jobs. The sextuplets sulk about this and go home and drink until they fall asleep. But when they wake up, a certain scene awaits them.
Bincho-tan, an orphan lives alone in the forest, she always has a piece of coal bonded on her head. Occasionally, she ventures into the town situated near the mountain, in search of work opportunities. In gratitude for her work, the townspeople offer her food as a gesture of appreciation. Bincho-tan leads a challenging life, but her joyful and warm demeanor endears her to those around her, leading her to make new friends. As time goes on, one after another heartwarming stories unfold, Bincho-tan finally illuminates her smile like a happy child.