Long ago, an existence known as Luminara appeared in this world. No one knows where it came from, what it truly was, or whether it still exists. Yet because of Luminara's appearance, the world became suffused with a mysterious power known as Mana.
Which was essential to use magic.
The monsters appear from another world through a crack that was created when the luminara appeared.
These cracks will form from time to time.
Mana could be divided into seven elemental types: the four primal elements—Fire (Red), Water (Blue), Wind (Silver), and Earth (Brown); a rare and mysterious form known as Healing (Green), attainable by only a few; and two ancient, enigmatic elements—Dark (Purple) and Light (Gold)—which no one had ever seen.
The protagonist's name is "Lee Hae-Won"; he is quite a timid person to others.
And Lee Hae-Won was 5 years old when he first discovered that he could see a wave of white light in the air, which was mana itself, which no one was able to see. His father had a red light around him, and his mother had a green light around her.