In the air, there is a "Box of Knowledge" that is shining with colorful lights. There are countless worlds, times and humans hidden in it. Dual (voiced by Risa Taneda) and Dorothy (voiced by Ayane Sakura) travel through the "Box of Knowledge" to fight against the viruses that are eroding each world. Any world contaminated by the virus must be eliminated as soon as possible. One day, the two sensed the emergence of a new virus, and they rushed over, only to find that the girl Limo (voiced by Yumiri Hanamori) was attacked by the virus. The girl has lost her memory and only knows her life. The first sentence she utters is related to the fate of everyone...