Isekai Cheat Kaitakuki summary:

I was living a life of a NEET, and I was supposed to have died suddenly because of my daily indolence - but when I woke up, I had become a baby. It seems that I was reincarnated in another world where magic exists. I was born the son of a lord in a remote village, and began to lead a second life with my beautiful mother Kara, my big-breasted maid and nanny Ruina, and my beautiful sister Amelia, who is not related to me by blood. As a teenager, I've grown up and enjoy my daily life in a different world using my top-level magical ability and modern knowledge...?JapanSpoilerニート生活を送っていた俺は、日頃の不摂生が祟り突然死したはずだった――が、目覚めたら赤ちゃんになっていた。どうやら魔法の存在する異世界に転生したらしい。辺境の村の領主の息子として生まれた俺は、美しい母親のカーラ、巨乳のメイド兼乳母ルイーナ、血の繋がらない美人妹アメリアらに囲まれて第二の人生を歩んでいく。成長した俺は、10代にして異世界トップレベルの魔力量と現代知識を駆使して、異世界での日常を楽しむが……!?