The central conceit of the episode is the extreme lack of presence exhibited by Junta Shiraishi. He is described as a "mob" character—a video game term for a background NPC—whose lack of presence is so severe that teachers mark him absent while he is sitting in class and automatic doors fail to open for him. This "superpower" of invisibility serves as a comedic foundation but also hints at Shiraishi’s internal resignation; he has accepted his role as an observer rather than a participant in his own youth.
Nagisa Kubo acts as the narrative disruptor. Unlike everyone else, she can see Shiraishi perfectly. Her role in Episode 1 is to challenge his status as a "mob" through a series of "wholesome teasing" vignettes. Kubo-san wa Mob wo Yurusanai Episode 1
Kubo Won't Let Me Be Invisible - Episode 1 discussion : r/anime The central conceit of the episode is the