<p>Robotic hands are central to a wide range of manipulation tasks, enabling human-like dexterity and adaptability. However, achieving such functionality with minimal actuation and reduced mechanical complexity remains a key challenge. Conventional approaches often rely on complex actuation mechanisms, resulting in increased system weight and limited integration flexibility. This study presents a lightweight, underactuated three-fingered robotic hand that incorporates tendon-driven actuation and compliant joint structures. A shared tendon-routing scheme enables synchronized finger flexion with a single actuator, while passive restoring forces are provided by rolling contact joints and elastic ligaments, removing the need for antagonistic actuation. All actuation components are embedded within the hand, resulting in a compact and portable configuration. Experimental evaluations demonstrate consistent finger motion, passive adaptation to varying object geometries, and the ability to perform multiple types of grasps with an underactuated architecture. These findings indicate the potential of the proposed design to serve as an efficient and compact solution for robotic manipulation.</p>