Since horses (Equus caballus) domesticated 5500 years ago, humans and horses have built a closed relationship.“Jinba Ittai”expresses this relationship, and it means “a feeling as if hearts of a human and a horse are united”. What kind of a sense is a “Jinba Ittai”actually, when a human is in contact with a horse? What kind of processes occur the sense of “Jinba Ittai”? In present study, we examine