While anime is well-recognized as a significant motivator of Japanese language learners today, idol fandom, though served as an equally strong source of motivation for some learners, receives far less academic attention. This paper is a preliminary exploration of idol fandom's role in fueling the Japanese language-learning process. Through conducting semi-structured in-depth interviews with two Japanese language learners who also identified as fans of ARASHI--one of the most popular idol groups in the Japanese entertainment industry--the author revealed that fandom (1) efficiently facilitated the learners' language-learning motivation along with a risk of demotivating them when a crisis occurred to the idols' career, (2) encouraged the learners to participate in creative language plays after they observed their idols' linguistic performance, and (3) allowed them to expand their social networking by exploiting their fandom as topics of conversation. As a language-learning motivator, idol fandom's dependence on external factors (e.g., the idols' activeness) makes it relatively unreliable, yet it gives learners agency in producing utterances in the target language when they look up to and imitate the native speaker idols.