This paper introduces the compass system, a log management system installed at Grand Front Osaka (GFO), where the indoor (location based) social networking service operates as the so-called Social City. It also verifies the effectiveness of the system, focusing on how effectively the compass system generates a location-based social graph. To this end, the study analyzes each user's operation log, including the check-in operation at the interactive digital signage terminals in GFO and/or in the mobile application installed in smart phones.