The premise of the first arc of "Eight Thorned Blades" titled "The Last Sky Of The Earth" is about the four once prestigious clans in Japan who were ambushed two years prior to the storyline and found refuge in the Philippines. The ambush annihilated almost all members of the four clans, with only a few surviving the devastating attack. But the peace and healing they've relished during those times in another country didn't last long as they all knew that their enemy—the group that initiated the attack in the first place to wipe out the entirety of the Shinomiya clan—also had survivors from that last attack. In addition to that, they slowly begin to discover a certain truth that leads back to a prestigious clan mentioned in a 300-year-old history and learning more about the people who could possibly revive it once again. But doing so will risk another batch of casualty, possibly even greater than how it was during the attack two years prior.

.

This picture is actually about the flower emblems of each clans within the Shrouded Flowers.