Zettai Sekai no Kuroi Tora - Realtime Classic

From Osuwari Team:

A young boy, Kanda Kazutora, moves from the city to his grandmother's home town. For some reason, he doesn't have memories of this town where he spent some time as a child. It is there that he meets a young boy, who is the same as he is, "being left out." The stage opens for these boys who can see the unseen.