This is a different method for rendering anime style hair specular. Instead of rendering the specular with shader, we will model and render it with the help of masking. Since the specular is a model, it will look sharp even in close up view. More over, we can rig and animate the hair specular.
Below is a brief explanation on using scene layer and render layer to setup this. It is similar with how to render eyebrow infront of hair setup.
VideoBelow are the viewport view on how the hair specular look like. The second video show a simple rig to control the direction of hair specular.
ReferenceDeviantArt Blender3D Anime Hair Specular
Youtube Blender3D Anime Hair Specular
Youtube Blender3D Anime Hair Specular with rig