You Are My Captive

The heir of the huge Fushiki corporation, Tomoe, comes to Japan as an exchange student. He is his father’s youngest child and on top of that - his mistress’s child, but he was still appointed as heir. There’s danger that people will aim for his life. They attach to him a new maid, with glasses, naturally clumsy and ill-mannered… who turns out to be his new bodyguard, defending Tomoe with her mop.

Wikipedia