The influence of Japonism, which is the post-mid-19th century phenomenon of appreciating and preferring the Japanese style that manifested all across Western art, started to grow as a result of the active open-door policy of Japan at this time. As all areas of Japanese arts and culture, such as paintings, sculptures and theater plays, influenced Europe and America, this influence developed into a cultural phenomenon that was reflected even in fashion. The characteristic elements of the kimono first expanded from Paris and showed a similar silhouette to that of the traditional kimono in the early 20th century, but towards the middle and the end of the century, kimono sleeves that were connected as one piece without a connecting seam line between the sleeve and bodice started to appear. The foundation of this research focuses on the design characteristics of kimono sleeves that can be seen in 20th-century fashion, and five varying kimono sleeve jackets and coats based on these formative characteristics were designed. Each design had a gusset design added, which improved the external and mobility problems inherent in kimono sleeve patterns, while at the same time serving as a proposal for new design element applications. Additionally, through various changes to and attempts at designs using the kimono sleeve as a limiting factor, new design possibilities were explored.