This study presents the development of a learning support system designed to help users of all ages—from children to adults—learn finger alphabets within a mixed reality (MR) environment. The proposed system incorporates two core functions: a finger alphabet example display function and a finger alphabet judgment function. The example display function overlays on the real-world view a reference image of the finger alphabet corresponding to the letter selected by the user. Meanwhile, the judgment function evaluates the user’s hand posture in real time by comparing the joint coordinate values of the fingers with a predefined dataset, and then superimposes the most closely matching character onto the MR space. By imitating the reference image and receiving immediate visual feedback, users can intuitively verify the correctness of their hand shapes and effectively learn the finger alphabet.