中学２年生の弟切飛（おとぎりとび）は、人外の相棒・バクと共に、失踪した兄を捜しながら憂鬱な日々を過ごしていた。
バク以外とはあまり話さない飛だったが、ある日突然クラスメイトの白玉龍子に声をかけられてから、少しずつ日常が変わり始めて…？
ひとりの少年が立ち向かう、「人」と「人外」を巡る冒険譚!!
Otogiri Tobi, a 2nd grade middle school student, spends his depressing days searching for his missing older brother alongside his inhuman companion, Baku. Tobi used to rarely speak to anyone besides Baku, however one day after his classmate Shiratama Ryuuko suddenly approaches him, his life begins to change…? This is an adventure surrounding the “human” and the “inhuman” that a lone boy faces.
