Ready-to-eat (RTE) foods have become an essential component of modern food systems due to urbanization, time constraints, emergency situations, and increased mobility. Retort processing enables the production of shelf-stable RTE meals with high microbiological safety; however, such products generally require external heating sources prior to consumption. This requirement limits their usability in remote, disaster-affected, and energy-deficient environments. A self-heating bento box addresses this limitation by integrating an internal chemical heating mechanism that enables on-demand heating without electricity or fuel. This research article presents a comprehensive study of a self-heating ready-to-eat bento box that integrates a chemical reaction-based heating system with retort-packaged food. The heating mechanism is based on the exothermic reaction between calcium oxide and water, while retort packaging ensures commercial sterility and extended shelf life. The article discusses the working principle, system design, retort packaging technology, thermal performance, safety considerations, environmental and sustainability aspects, economic feasibility, HACCP and FMEA analysis, applications, limitations, and future scope