This thesis examines wasei-eigo, a distinctive blend of English and Japanese that straddles the line between loanwords and newly coined terms. To provide a closer explanation of this phenomenon, the thesis begins with an overview of the history of how foreign words, with an emphasis on English, have been absorbed into the Japanese language, reflecting cultural changes in Japan. Throughout the integration of English into Japanese, this interesting phenomenon creates English-like terms which can be puzzling to native English speakers. The thesis also explains the difference between wasei-eigo and gairaigo (“true” loanwords), with a focus on the changes these terms underwent to adapt into the Japanese language, such as phonological, morphological, and semantic changes. The thesis gives numerous examples of both types of loanwords and highlights the extensive influence of English as a global language, while also showcasing the richness and cultural uniqueness of Japanese language and its development over time. Ultimately, the study emphasizes that wasei-eigo is more than just a linguistic phenomenon; it is a significant cultural marker that illustrates Japan’s unique way of blending foreign influences into its own language and society.