The Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) is a 10-year 6-band survey that will map ~30,000 sq-deg of the sky, giving us an unprecedented level of statistics for cosmological studies. In this work, we use the public data from the Hyper-Suprime Cam Subaru Strategic Program (HSC-SSP) to perform a joint analysis of galaxy clustering, galaxy-galaxy lensing and cosmic shear (3x2pt) in harmonic space. The aim is three-fold: i) The HSC-SSP data is of comparable depth to LSST, and is processed with the LSST Science pipelines, giving us an insight to the features and level of statistics that we expect in the LSST data. ii) Development and testing of the 3x2pt analysis pipeline by the Dark Energy Science Collaboration. iii) Use the 3x2pt analysis to obtain constraints on cosmological parameters from the redshift/magnitude window opened up by HSC’s unique depth.