The Creatures in Grey, Red, Blue & White

This is a another GATE Fan Story.

After the massacre in Japan the unknown forces has launched in Ginza that failed severely, Japan's Government deploys the JSDF to investigate the building called GATE that would lead themselves to another world called 'Special Region'.
After setting Headquarters at an area called 'Alnus Hill' and held against the unknown forces' ambush easily at night without depleting too much ammo and shells, we all know what comes next. Alnus Hill would be a refugee city for Special Region pass - by, and the Empire would make a peace treaty with Japan at the end after a devastating sabotage and take over by the Prince of the Empire.

But let's go when before the Bandit Assault at Italica. It's unsatisfying or boring who already read or watched series.

Something odd is happening far at a 'peaceful' green grass area at Alnus Hill.
Strange blue lights would blink once a night at that area. Making the Soldiers of the JSDF concerned, alerted and worrying for the Special Region Refugees.
But, it's not that concerning. It doesn't show red, or any color besides blue.
That's where this alternative story begins.

Author's Note:
All Artwork, Creations does NOT belong to me. They belong to their respective creators/owner/authors.
Universal Union & Half Life belongs to Valve
GATE belongs to the people from Japan