Elevation of Mana - Agent Wandering

When a college student takes a shortcut through the woods, he discovers a strange new world, in this Melody of Mana prequel series. 

Heading home after a long day of classes, tech student Justin takes a little-used path through the woods. But when he stumbles unexpectedly, he rolls downhill and into the challenge of a lifetime. Faced with exotic, glowing plants he’s never seen before and a luminescent pool of crystal-blue water that exerts a frightening pull over him, he’s literally reborn in a rough, raw landscape—in a time before history began . . .

Reduced to a helpless child but somehow retaining his adult memories, Elian—as he’s now known—must come to know the family that has claimed him, all the while learning a strange new language and the culture of this foreign land, where he must survive until he can attempt to return home. But most importantly, he must master the light that surrounds him, an exhilarating magic called mana that will shape his future, if he’ll only grow up.

Through concentrated apprenticeship and some calamitous mistakes, Elian will finally become a young man again. And just in time to help his people face a dangerous force that threatens their small kingdom.