いいご身分だな、俺にくれよ ～下剋上揺籃編～, Legend of Issac

Osamu Takahashi dies in an accident and is reincarnated as Isaac, the second son of the Wellrod Marquis family, in the world of a certain romance game. However, his new life is far from easy—he is bullied by his older stepbrother, and his first love already has a fiancé. Aware of the harsh conditions even in this other world, Isaac makes a bold decision: "What a nice life you have. Give it to me!" He murders his stepbrother and sets out to rise to power through cunning schemes and ruthless ambition. Thus begins the "Cradle Arc" of Isaac's underdog rebellion!