The Spear User that Couldn’t Become the Hero 《Protagonist》

The Spear User that Couldn’t Become the Hero 《Protagonist》 summary:

In 2031 A.D. mysterious crystal bodies referred to as 『C.E.』 attacked. Humanity was gradually pushed down the road to ruin.
This is the story of a great hero who save the Earth from destruction with his shining holy sword――not.
In history during humanity’s grimmest hour, this is the story of the overshadowed hero, a lone spear user.
In often cases, this would be a story about a cheat protagonist and his harem; but, this story is from the point-of-view of a supporting character that shows the conspiracy behind such plots.
Basically, the theme is school battles.