Right after jumping off the roof Masamune was caught up in his class transition to a new world.
A throne hall.
The students had all received high-class jobs such as Sage or hero. Except for Masamune, who became a healer, the weakest known occupation.
Cursed at and called incompetent, he alone is banished. After wandering in the darkness, Masamune who received the skill [mischief inversion {extreme}] through inverting the healing magic gained the ominous magic [Encroachment Wave].
Now the strongest, Masamune swore his revenge.
Demons and the white cat tribe, precious companions he met on his journey. Together they explore the new world.