Ze verloor van haar zus, die op haar beurt in de finale verloor van Jamie Loeb.[9] Op ITF-niveau won Naomi Osaka nooit een titel, al bereikte ze wel vier finales. Haar eerste twee finales kwamen in $25k-toernooien, waarvan de eerste plaatsvond in juni 2013 in El Paso, Texas. In maart 2014 ze in eerdere rondes onder anderen haar zus en Lesja Tsoerenko had verslagen.
Her best result of the 2012 season came at the ITF $10K event in Amelia Island, where she lost to her sister in the semifinals.[1] Osaka has never won a title at the ITF level, only managing to finish runner-up on four occasions.[1] Her first two finals came at the $25K level, one of which was in June 2013 in El Paso, Texas. The other was in March 2014 in Irapuato, Mexico and included a victory over her sister.[1]ParaCrawl Corpus ParaCrawl Corpus