M. Nagamachi founded Kansei Engineering at Hiroshima University about 30 years ago and it has spread out in the world as an ergonomic consumer-oriented product development. The aim of the kansei engineering is to develop a new product by translating a customer’s psychological needs and feeling (kansei) concerning it into design specifications. The kansei data are analyzed by a multivariate statistical analysis to create the new products so far, but the kansei data not always have linear features assumed under the normal distribution. Rough sets theory is able to deal with any kind of data, irrespective of linear or non-linear characteristics of the data. We compare the results based on statistical analysis and on Rough Sets Theory.