The year is 2061, when space travel is now possible and commercially viable, and the students of Caird High School embark on their Planet Camp. But soon after Group B5 arrived at their planetary camp site, a mysterious and unforeseen sentient light sphere warps its 9 members into outer space, stranding them 5012 light years away from their home planet. With the discovery of an old, unmanned spaceship nearby, the students must stay strong, manage their limited resources and remain united in the darkness of space, so that all of them can survive their long and likely perilous trek back home aboard the Astra.

Ashiya has spent the first seven days of high school stuck in the infirmary because of a youkai attaching itself to him. He ends up asking the owner of a small tea room called the "Mononokean" for help. This is a tale involving the very morose owner of Mononokean guiding the youkai that happened to wander into this world go to the next world.