Wa no Kage

Wa no Kage summary:

Set in a world that has a ring encircling the planet, there is a nation that follow the tradition of chasing the shadow cast by this ring. They go as far as the ends of both northern and southern edges of the continents to accomplish their 'shadow chasing'. For what reason? Who knows. What is known about this nation is that they have been able to preserve their small nation in so small part to their advanced understanding of the 'Corona Solids', which have been utilised to build an array of creations, most notably the 'hakukai armour', which enables its user to enhance their natural ability, as well as create weapons out of this special creation. However, it seems that a storm is brewing upon this nation...