The Mechanical Kansei means a decision capability to evaluate an impression unconsciously, intuitively with informational synthesis in order to mechanics. In a product conceptual design, to create structural shape and layout as solution principle from functional requirement is greatly dependent on the accumulated engineering knowledge, experience and know-how. These engineering senses are called as the Mechanical Kansei. If the Kansei cannot be well used to design product structural shape and layout which satisfied various functional requirements, its design process has a difficulty to draw creative structural shape and layout. In this study, we propose the new methodology of the interaction of a functional design and a structural design in a product conceptual design process for decision making of product design concept based on the Human Computing Interaction. This proposed system creates shape and layout imagery to interact between the Mechanical Kansei and topology optimization method based on the Fully Stressed Design. The response of the Mechanical Kansei is obtained by using Brain Machine Interface (BMI) from the Frontal Cortex handles a positive expectation and the Supplementary Motor Area is assigned to the physics simulation within a brain. The shape and layout imagery creation system is discussed via the verification result and the creation results. We confirmed that the system has created the shape and layout considering the Mechanical Kansei for the product conceptual design, and also it's an attractive product design structure.