The world is in peril as gates begin to appear all over, bearing poisonous seeds and dangerous beings.
Five heroes are summoned.
Each hero forms a party and sets out to rid the world of the gates, the bridge between the human and Devil Emperor dimensions.
The Sword Hero accepts an ordinary level two orphan teenage boy, Ingal, into his party due to unexpected circumstances.
Ingal sets out with the Sword Hero's Party as an ordinary member with the sole duty of carrying their luggage.
Sword Hero Morningster Accomplishes feat after feat as time passes, growing stronger, saving kingdoms, defeating boss monsters of gates, and closing them.
However, he soon begins to question if these victories are truly his.
He questions why he awakens at certain periods to find the corpses of powerful boss monsters lying before the gates without any memory as to how he defeated them.
A constant occurrence was the face of the smiling teenage boy he would awaken to...
"What is your true Identity, Ingal?"