Natural fiber-reinforced polymer (NFRP) composites pull attraction among lightweight structures in various studies both for academic and industrial research. The interest has risen due to its NVH (noise, vibration, harshness) and lightweight advantages in comparison to glass fiber and carbon alternatives. NFRP composites offer a surface structure on micro level that provides excellent bonding to polymer media without the need of sizing. Blends of carefully formulated kenaf, hemp, flax, jute, and other fibers in combination with appropriate thermoplastic matrix constitute composites laminates with performance characteristics such as formability, rigidity, and impact resistance. This study comprised the investigation of IR pre-heating and injection molding process parameters of natural fiber-reinforced composites with innovative contribution of overmolding method. Fiber form technology enables to adapt injection overmolding method to combine the high processable thermoplastic melts with the thermoformable NFRP composite sheets for multi-functional hybrid part production. To understand the adhesion development through overmolding, a non-isothermal screening procedure for bonding molten polypropylene (PP) to a IR heated thermoformable NFRP sheets has been developed. The method has been implemented to optimize boundary process temperatures for good bond formation as a function of NFRP sheet composition while optimizing IR heating system and injection cycle. Specimens as output of optimized series of trials, have been isolated from composites and tensile strength, impact resistance, and shear adhesion strength tests have been performed based on the ASTM D638, D7136, and D3163, respectively. This investigation allowed us to identify an ideal setup consisting of individual process and application temperatures for NFRP sheet and molten PP for ideally bonded composite-polymer hybrid part, results will inspire further studies on exploring boundaries of lightweight design