The Japanese Holly is an ideal alternative to the Box hedge, due to it being very similar in nature (even though it is a type of Holly) and has added benefits- being resistant to Box blight, regenerates from old wood (meaning you can re-shape it easily if it has been neglected for a while) and does not get leaf scorch when pruned. As well as this, the Ilex Crenata is also slightly more adaptable to tougher conditions than the Box, meaning it is great for Colder areas.
You can keep the Japanese Holly as a small, neat hedge, or make it part of a lovely edging to a border/path. Even consider growing it to be a bit higher (around 1m), and trim into a topiary shape.