Twenty-two-year-old college dropout Tatsuhiro Satou has been a hikikomori for almost four years. In his isolation, he has come to believe in many obscure conspiracy theories, but there is one in particular that he holds unshakable faith in: the theory that the evil conspirator behind his shut-in NEET (Not in Employment, Education or Training) status is the Nihon Hikikomori Kyokai (NHK)—an evil and secret organization dedicated to fostering the spread of hikikomori culture.

NHK ni Youkoso! is a psychological dramedy that follows Tatsuhiro as he strives to escape from the NHK's wicked machinations and the disease of self-wrought isolation while struggling to even just leave his apartment and find a job. His unexpected encounter with the mysterious Misaki Nakahara might signal a reversal of fortune for Tatsuhiro, but with this meeting comes the inevitable cost of having to face his greatest fear—society.