Glass mask is one of the best shoujo manga out there. Despite having a common enough shoujo setting, the plot hardly ever falls into any of the comon cliches that shoujo manga often times fall into. The artwork is in a classic 80s style, nothing outstanding, but the mangaka does not skimp on the minor details, and her understanding of common facial expressions is top notch.
Where Glass Mask really stands out is in the main characters and in the story. We are presented with a main character that is hard not to sympathize with and all the supporting characters and antagonists are really well fleshed out and have realistic and human personalities. The plot arc is interesting, each mini-arc has trials in the main characters confidence and abilities which she eventually solves to our amazment and the amazment of the audiences. The main arc slowly building until half way through where there is an impending crisis.
Glass mask's theme of working hard, having natural talent, and succeeding despite lacking beauty or grace make it one of my favorites and mark it as something that every shoujo fan should at least try.