Tasuku Sato

Hiroto, a kind and earnest older brother and his autistic younger brother, Michito, led an ordinary life together -- until one day, a five-year-old boy appeared at their doorstep claiming to be their nephew. This boy, who refers to himself as "Lion," says he is the son of Hiroto and Michito's sister, who they believed was dead. However, she was actually alive only to vanish again, entrusting her young son to the brothers' care. The trio develop a strong camaraderie as they seek to unravel a thicket of lies and a grand scheme of love, surrounding the mysterious sister.