Arena of the Gods

In the future world's Arena of the Gods, one can summon a deity by calling its name and win rewards for victory. Ten years ago, the protagonist's father called the name of a stone monkey but received no response. Ten years later, the protagonist, once again shouldering the responsibility, walks this path. He discovers the secret of why the gods do not respond, begins to free the deities, takes on the heavy burden, and starts an epic song of triumph.