Kitakami Yoru is the ultimate loser: overweight, socially awkward, and the target of relentless bullying at Tokyo's elite Shuchiin Academy. During a school spring trip, a series of unfortunate events leads to a catastrophic misunderstanding with Kasumigaoka Utaha, a brilliant but sharp-tongued author. Convinced he is a perverted stalker, she publicly humiliates him, cementing his status as a social pariah.

Yet, Yoru harbors a bizarre secret invisible to everyone else: he can see glowing treasure chests hovering above people's heads, seemingly containing their hidden regrets or potential. As he navigates the treacherous social hierarchy of noble students and encounters famous heroines from various stories who seem to inhabit this world, Yoru remains misunderstood and despised. However, the chests suggest a deeper truth behind their cold exteriors.

While Yoru resigns himself to a life of infamy, the heroines begin to uncover clues that their judgment of the 'disgusting otaku' was gravely mistaken. In a twist of fate, the very girl who crushed his spirit may soon be the first to drown in remorse as the reality of his innocence—and his unique ability—comes to light.