Bug Ego follows Makoto Hitsujiya, a kind-hearted high school transfer who stumbles upon the bizarre world of Bugs—reality-warping glitches triggered by specific, often mundane actions. When reclusive classmate Takehiro Kokudou enlists Makoto’s help to test these quirks—from harmless pranks to unsettling coincidences—the two form an uneasy partnership. Together, they chase the thrill of each new discovery, all while navigating the strange side effects that ripple through their everyday lives.

At the story’s center is Makoto, whose curiosity and empathy both fuel and complicate their exploits. Kokudou, shy and obsessed, meticulously catalogs each Bug as if solving a puzzle, drawing Makoto deeper into his secret notebook. Supporting them is Yuki, a perceptive friend who begins to piece together the pattern behind these anomalies, and Moesawa, a quiet classmate whose role hints at greater significance. Their high school—a backdrop of classrooms, vending machines, and empty hallways—becomes a stage where ordinary routines collide with surreal distortion.