Okami Wa Nemuranai - Chapter 14.1-2

No one knows when the first Clough door appeared. All people know is that a new era began when it was pushed open.Fortresses, sublimators, pillars of star essence, three-dimensional armaments, infinite energy, who can escape the sweeping tide of the times?In the abyss, the reverse realm, the skins, the alien gods, the mad king, the rulers, and the dark creatures, all howl in madness!Inside the black mist, the demons and ghosts crawl forward as a cross-dimensional migration silently brews.

Sam Sanderson is envied by many for his job, however he himself didn't seem to like it much.

Due to his expertise in nanotechnology he was tasked with monitoring the state the Valkyries, humanity's strongest weapons who all just happen to be made into gorgeous females.

Forbidden from even touching any of them, Sam spends his days in agony watching flowers he couldn't hope to touch. However one day all of that seemed to change.