On a sweltering summer day, Yoshiki realizes that his best friend Hikaru—who had smiled beside him throughout their childhood—is no longer the same. Though this "Hikaru" looks and talks just like him, it's something else entirely. In their stifling, isolated village, Hikaru was the only person Yoshiki could ever truly trust. Desperate not to lose that bond, he chooses to accept the imposter—and vows to tell no one.

As Yoshiki watches Hikaru happily eat a slice of watermelon, he's struck by a memory of the real Hikaru. A quiet guilt begins to gnaw at him as he's reminded that the real Hikaru is already gone–is it really alright for him to enjoy a "normal" life without him...? Unaware of Yoshiki's inner turmoil, Hikaru smiles at him and earnestly says, "Just being with you makes me happy." Overwhelmed, Yoshiki reaches out to Kurebayashi, a housewife he encountered at the supermarket.