Electrogenic Na(+)-coupled sugar symporter that may play a primary role in D-mannose and possibly D-fructose and D-glucose transport at the plasma membrane. Transporter activity is driven by a transmembrane Na(+) electrochemical gradient set by the Na(+)/K(+) pump. Exclusively recognizes sugar substrates having a pyranose ring with an axial hydroxyl group on carbon 2. {ECO:0000269|PubMed:15607332, ECO:0000305|PubMed:35077764}. This is the function of ENSG00000117834 (SLC5A9, solute carrier family 5 member 9).