Managing negative emotions and promptly relieving anxiety are two main focuses in the prevention of mental illness. This paper indicates a biofeedback-training experience that helps an experiencer to manage his/her emotions. The authors have defined the following major problems to approach this bio-feedback design procedure. The first one is how to grasp human emotions using existing technologies in exhibition circumstances. The second one is what kind of manifestation should be used to create emotional resonance. For the first problem, Heart Rate Variability (HRV) is adopted to obtain anxiety and stress levels. For the second problem, the authors took a nature-inspired design approach. The results are visualized on a wall composed of 64 bionic scales. A device system guides the experiencer into a meditative state, and contributes to spurring thoughts on emotional management, and thus achieving the purpose of preventing mental illness.