The first arc will destroy you, and nothing else in anime hits that specific kind of grief, watching something learn what love is only to lose it forever. Fushi doesn't grow stronger through loss; he grows sadder, and the show refuses to let that sadness mean anything beyond itself. Later episodes falter badly, trading emotional precision for plot, but those early chapters sit in your chest long after they end.

An immortal entity is sent to Earth with two abilities: it can take the shape of whatever stimulates it, and it returns to life after dying. Beginning as formless matter, it gradually gains consciousness through a wolf's body before taking human form as a boy named Fushi. Alone and confused, Fushi stumbles through existence with the mind of an infant trapped in an increasingly complex world. What transforms Fushi from a blank slate into something approaching human is connection. The kindness of the people he meets teaches him how to survive and helps him grow as a person. Yet this awakening comes at a cost. A mysterious and destructive enemy called Nokker threatens him, and he suffers painful separations from the people he loves. Fushi's journey becomes a meditation on what makes life worth living when you cannot truly die. Is immortality a gift or a prison? Can love exist without the possibility of loss? The series balances wonder and heartbreak as Fushi meets all kinds of people in many places across time.