The current dissertation investigates factors that influence usages of Japanese honorifics and explores how instructors can introduce honorifics more effectively to second-language learners. Apart from existing literature, my data includes a corpus of real-life usages of Modern Japanese, classroom observations, interviews with Japanese language instructors, and a workshop conducted as an implementation of new pedagogy. I first examine the definition of honorifics and relevant concepts such as expressions of personal treatment and speech levels. Using diverse usages in real life, I examine multiple layers of meanings associated with honorifics and propose factors that influence usages of honorifics. My analysis suggests that usages of honorifics do not always match their labels, and that honorifics may be used for various purposes. In the latter half of this dissertation, I lay out existing pedagogy and discuss challenges in teaching Japanese honorifics. In addition, how mainstream textbooks introduce honorifics is also reviewed. After qualitatively discussing first-hand data, I make suggestions for introducing Japanese honorifics to learners of different proficiency levels. Bridging latest research on honorifics to teaching practices in second-language classrooms, my main teaching goal is that students will be able to use honorifics to express themselves instead of blindly following normative rules introduced in textbooks. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]