Recently, a wearable body-sensor network realized continuous sleep monitoring by ExG (EEG, EMG, EOG, and ECG) extraction from a sleeper's face. At least 14 sensors were placed on the face, and were managed by a network controller for sleep monitoring. However, the system was too bulky and heavy (127x63.5χ28mnf, 210g) to wear during sleep, and consumed high power (>;100mW). Another system used a CMOS IC sensor for smaller power consumption (5 to 10mW/sensor), but it was still inconvenient to wear due to its cumbersome size (49χ19χ6mnf). This paper presents a 5g sub-500μW compact sleep-monitoring system based on a low-power network controller and ExG sensors, and Planar Fashionable Circuit Board (P-FCB) technology. The entire sleep monitor operates on a 1.5 V 10mAh single tiny coin battery (φ=5.8mm, T=2.1 mm, 200mg) stacked on the controller chip. The power dissipation of 14 sensors and a controller is below 425 μW, which is <;1.5% of previ ous works. Its low power consumption is possible by the Linked-List Manager (LLM)-based protocol such as Adaptive Dual-Mode Control (ADMC) and Continuous Data Transmission (CDT), and low-swing clock and data transceivers.