Learning Japanese can be challenging, but the speed at which someone can learn depends on several factors. Motivation, learning style, prior language experience, language difficulty, proficiency levels, classroom vs self-study, immersion, frequency of practice, learning resources, language goals and practice opportunities all play a role in how fast someone can learn Japanese. Consistency is key when it comes to language learning, and learners who maintain their motivation and persevere through challenges will likely make steady progress towards their language goals.