Yozakura Quartet, Volume 17 (Yozakura Quartet #93-99)

The Seven Pillars, a testament to the Hiizumi branch family's grudge for having been forcibly sent to the other realm, and whose blossoming marks the very end of the world. In an effort to thwart the oncoming threat, an ultimate weapon, Pillar Zero, was devised. However, many sacrifices were required in its creation. This is the story of the people who wagered everything in order to complete Pillar Zero, with the duty-bound Hiizumi clan and Iyo family standing at its core.