To increase the scientific return of sample return missions, we aim to maximize the information gained from individual minerals. One mineral system that records a range of pre- and post-accretionary histories are the Fe-sulfides. The compositions, morphologies, and crystal structures of sulfides are determined by their formation conditions including temperature, time, oxygen and sulfur fugacity, and aqueous and thermal history. We propose to investigate the structures, compositions, and context of sulfide minerals in samples returned by Hayabusa and compare these with sulfides in chondritic meteorites. Previous work on Hayabusa samples (asteroid 25143 Itokawa) implies their sulfides formed by thermal metamorphism (being LL5-6 material). We will constrain parent body formation conditions of asteroid Itokawa by studying analogous sulfides with petrographic context in chondritic meteorites. We will study the composition, texture, and crystal structure of sulfides from LL3-6 chondrites and sulfide-bearing Hayabusa samples requested here via transmission-electron microscopy, to investigate correlations between formation mechanism, oxygen and sulfur fugacity, temperature, and cooling rate. By studying sulfides in Hayabusa particles, we will constrain the conditions of formation and parent body processes of asteroid Itokawa.