I only remember vague details about MC's original world aka last arc. MC was a scientist / researcher or smtn. A female assistant/intern in MC's company stole the chip he invented. He died in an accident or explosion. Also there's family drama regarding MC's identity ...like he's the son of a prestigious family but was seperated from his parents (not sure about this though). Found it. It's There's always a protagonist with delusions of starting a harem.