This randomized, multicenter interventional study evaluates a combined forest therapy (shinrin-yoku) and mindfulness-based program in adults with high sensory-processing sensitivity confirmed using a validated instrument. Participants are randomized (1:1) to either a forest-based intervention or an active indoor sensory control condition. The intervention is delivered over approximately 22 weeks according to a predefined protocol, with assessments conducted at baseline and at the end of the intervention.