|Various factors that exert an influence on foreign Korean-language learners’ achievements have long been studied. Recently, to obtain a better understanding of differences in learning achievements, studies have begun comparing learning achievements between learners in the same educational environment. In this study, we examine whether there exists a difference in academic achievements between genders and between Hanja and non-Hanja culture learners. We also investigate whether those who have received Korean language education from basic to intermediate level with identical textbooks and identical curricula have higher academic achievements than those who have not received such education. To this end, using the linear mixed model, we conducted a statistical analysis of Korean-language fulfillment score data collected from a Korean-language institute administrated by K-university. We found that the high-scoring group tended to make slow, constant progress with regard to advancing to Korean-language level, whereas the low-scoring group tended to withdraw after a significant degree of achievement. Additionally, female learners performed much better than male learners in the high-scoring group, but in the low-scoring group, much poorer performance was observed. Finally, we found that it is a better strategy to start learning Korean from the basic level to the intermediate level at the same university.