Sari Rasa Restaurant is a Chinese food restaurant located in Jepara City. This family business has been operational for 16 years and is currently facing tight competition in the marketplace. In this study, the researcher wants to inquire into the factors that contribute to the competitive advantage of Sari Rasa restaurant by employing a single instrumental case study research involving interviews, observations, and field notes. The owners, employees, and customers are approached for this study. The latent variable produced (Core Competency, Recruitment Problem, Communication with Customer, Quality Control, New Innovation, Leadership, Service Performance, WOM (Word of Mouth), e-WOM (Electronic Word Of Mouth), Original Chinese Flavour, Service Improvement, Quality Product and Taste ) evince a mini-model theory that guides Sari Rasa Restaurant in enhancing its competitive advantage. This research can be continued by academicians and produce the grand theory that later could be used by other family business owners who want to start a restaurant business.