Adult PC Game: AlterEgo by Kiss Archive

Nagare Hiiragi used to have a special power. He lost it a while ago and now lives a peaceful life as a student.

He has a secret ambition to destroy the Hiiragi family and be free from their curse. To achieve it, he needs to erase his father, but he can't do that...

One day, he gets involved in a trouble. As he beats demons using his new power, he is saved by someone unknown. He finally gets to know the fact that the root of every evil is his father and he makes up his mind to take action to free himself and his older sister from the Hiiragi family...