Talentless Nana unfolds in a world transformed fifty years after horrific creatures known as the "enemies of humanity" began appearing across the globe. To fight them, special academies were created to train teenagers with supernatural gifts called "Talents," powers that can include pyrokinesis, time travel, and other abilities that place them beyond ordinary people. On one such secluded island campus, students are taught to see themselves as humanity's future defenders.
Nanao Nakajima stands apart from his classmates because he has no Talent at all. Often singled out for bullying by the other "Talented" teenagers, he still pushes himself to complete his training and find a place among them. The class dynamic changes when two transfer students arrive: the mysterious Kyouya Onodera and Nana Hiiragi, introduced as a mind reader. Alongside classmates such as Michiru Inukai, the students' daily routine begins to fracture as a string of unexplained disappearances shakes the island. What begins as preparation for a distant war turns into a tense struggle shaped by distrust, manipulation, and the fear that the real threat may be much closer than anyone expected.