It is well known that the shape (appearance) is one of the components showing the beauty of Japanese swords. Furthermore, the famous and historical Japanese swords are considered to have more elegances and dignity. Currently, the superiority and inferiority evaluations of modern Japanese swords are performed by experts who have deep knowledge, and these swords are ranked the values according to each expert's sensibility. However, it is difficult to understand these evaluation results for ordinary people who are not familiar with them. Therefore, this study aims to analyze the shape of the modern Japanese swords as well as to propose the design approach using neural networks. In addition, we measured the cross-sectional features of the modern Japanese sword by laser displacement sensor and elucidated the relationships between the length and the cross-sectional features with the curve fitting method. As a result, we can succeed in the optimum design of the modern Japanese sword based on our analysis. Finally, our designed modern Japanese sword was exhibited in the contest held in 2021, and its good effectiveness was verified by the experts.

日本刀の美しさは評価者らの感性（経験知）に基づくことから，評価者によって結果が異なる場合が多い．一方，熟練工不足問題を抱える我が国製造業にとって，感性の可視化手法が将来の自動化に繋がると考えられる．したがって，本研究では被験者の経験知を問わず日本刀を鑑賞できるVRシステムを開発した．このシステムの体験会を一般人，鑑定者，刀職者を対象に実施することを通じて，感性評価の可視化を試みた結果を述べる．

The evaluation of the beauty of Japanese swords relies upon the subjective sensibilities of experts; that is, this evaluation differs depending on the importance an expert places on the components of beauty. This study examined the Kansei evaluation of Japanese swords from the perspectives of both experts and novices. A virtual reality (VR) appreciation system was constructed to view Japanese swords housed in a museum and simulate holding them using a VR headset. After this viewing experience, a questionnaire was administered to novices and experts to compare their Kansei evaluation of Japanese swords. Multiple regression analysis and text mining were conducted to identify the components that influence this evaluation. This study determined that the Kansei evaluation of Japanese swords was influenced by the component of beauty, and the evaluation differed based on evaluators' experiential knowledge of Japanese swords. The experts in this study presented more negative opinions about VR systems compared with the novices, suggesting that skilled craftsmanship is not easily represented via VR.