SIFU is a method for reconstructing high-quality 3D virtual human models from lateral images. Its core innovation lies in proposing a new implicit function based on lateral images, which enhances feature extraction and improves geometric accuracy. Additionally, SIFU introduces a 3D consistent texture optimization process that significantly enhances texture quality and enables texture editing through a text-to-image diffusion model. SIFU excels in handling complex poses and loose clothing, making it an ideal solution for practical applications.