By isolating a finite effective volume from a conventional triangular pyramid corner cube, we obtained truncated corner cube structures with greatly enhanced retroreflection efficiency. We explore an optimal truncated corner cube with near 100% retroreflection efficiency based on the expectation that the traveling paths of the optical rays can be localized in the finite effective volume of the structure, and, as a result, truncated corner cubes with perfect efficiency can be produced. As a case study, the retroreflection efficiency of a commercialized 3M truncated corner cube sample is evaluated. Furthermore, it is shown with numerical verification that a truncated corner cube array sheet with near-perfect retroreflection efficiency can be produced.