The theory of Stark systems due to Burns, Sakamoto, and Sano is an important tool toward main conjectures in Iwasawa theory. In this paper, we propose a new perspective of their results, which produces more refined consequences. As a principal application, we prove one divisibility of the equivariant main conjecture for elliptic curves, under certain conditions without μ=0 hypothesis. This research was supported by JSPS KAKENHI Grant Number 19J00763.