"Aizawake no Etcetera" centers on Aizawa Kei, a high school student who lives a seemingly ordinary life but is burdened by an unusual condition: he can see the "weight" of people's emotions as physical objects. These manifestations, which range from small trinkets to massive, cumbersome items, represent the emotional baggage individuals carry. Kei’s ability isolates him, as he struggles to navigate the complexities of human relationships while being constantly reminded of the hidden struggles others face.

The narrative explores Kei’s interactions with classmates, family, and strangers, each of whom carries their own emotional burdens. His childhood friend, Yui, is a central figure in the story, often serving as a grounding presence despite her own unresolved feelings. Another key character is Haruto, a transfer student whose emotional weight is unusually heavy, prompting Kei to delve deeper into the mysteries of his ability and the nature of human emotions.

As the story progresses, Kei learns to confront his own emotional struggles, which are symbolized by a particularly heavy and enigmatic object he carries. The series delves into themes of empathy, self-acceptance, and the invisible burdens people bear, blending slice-of-life elements with subtle supernatural undertones. The plot unfolds through episodic encounters, gradually revealing the interconnectedness of the characters’ lives and the impact of Kei’s ability on his understanding of others and himself.