半年前に禁足地の山中で行方不明になった「光」に代わって現れた、声や見た目はそっくりだが光ではない〝ナニカ〟。無垢で好奇心旺盛に見える。

"Something" that appeared in place of Hikaru, who went missing half a year ago in the forbidden mountains. It looks and sounds exactly like Hikaru, but isn't him. It seems innocent and full of curiosity.