Effective risk communication is essential for disaster risk management. Apart from empowering communities to make informed risk choices, risk information disclosure can also drastically enhance their disaster preparedness, especially concerning conjoint scenarios of technological and natural hazards (Natech). A fundamental precondition is the actual demand for such information. This study ventures to assess whether residents around Osaka Bay have this demand, or “appetite,” for risk information disclosure, as well as to understand their communicative behavior and perceived challenges in the Japanese context through the prism of the Situational Theory of Problem Solving. To test this framework under realistic conditions, data were collected through a household questionnaire survey from two urban areas near industrial complexes in Osaka Bay. The results show that identifying Natech risk information deficiency as a problem was not a statistically significant predictor for individuals’ motivation to communicate. However, their motivation increased as their perceived personal involvement with the situation rose, while the perceived obstacles in doing something about it exerted a negative influence on their motivation. Individuals’ motivation intensified their communicative actions to solve this problem. Public segmentation underscored the elevated public perceptions concerning the issue of risk information deficiency in nearly nine out of ten respondents. These findings indicate a strong community appetite for chemical and Natech risk information, which subsequently led to high situational motivation to engage in communicative action, particularly information acquisition. Risk management policy is suggested to focus on introducing chemical risk information disclosure regulatory initiatives to encourage citizen engagement.