AIBOU: X-DAY: Detective Kenichi Itami from the The National Police Agency and Akira Iwatsuki from the cyber investigation team investigate a complex murder case. The victim was under investigation by the cyber investigation team. As Detective Kenichi Itami and Akira Iwatsuki delve deeper into the case, pressure from around makes their investigation even more difficult. Secretly, a national financial doomsday scenario is carried out under the plan of "X Day".