Complex sentence: In 1984, Kagoshima city council and Japanese National Railways, the precursor of JR, made this plan public, and in 1990 it was decided that JR and local department store Yamakataya would be the co-tenants.
Split into simpler sentences: In 1984, Kagoshima city council and Japanese National Railways, the precursor of JR, made this plan public. In 1990 it was decided that JR and local department store, Yamakataya, would be the co-tenants.