As the name suggests, Ontic Structural Realism (OSR) entails the claim that structure is all there is. However, several critics have argued that OSR’s ontology is incomplete. There must be something ontologically significant beyond structure. I will suggest an ontology for these critics, one that invokes what Ladyman and Ross call “Kantian residue”. In doing so, I modify Rae Langton’s Kantian humility thesis to incorporate some extra-structural noumenal “something=x” (as Kant puts it). This involves positing (a) that a mysterious something=x exists and (b) that something=x is responsible for structure (specifically structure’s non-arbitrary properties). Responsibility is a modal relation that is potentially equivalent to some asymmetric relation (causation, explanation, determination, grounding, or the like). Regarding the nature of something=x, I argue in deflationary spirit that we can only know that it is that which is responsible for structure.