What is the best priced uncomplicated health insurance in Tokyo, Japan?

1. I am a mid 20s foreigner living in Tokyo. 2. I know the Japanese company I am working for pays the national health insurance scheme but I also know that it wont cover 100% of my hospital bills. 3. Out-patient benefits are not really necessary but welcome if its included. All I want is my in-patient bills will be 100% covered. 4. What insurance company can you recommend that wont hurt my wallet too much? thanks
--------------------
I have never heard of that kind of private health insurance in Japan. Private health insurance in Japan would provide benefit like 5-10K yen for each day if you are hospitalized (stayed in a hospital) or had a surgery. But there is nothing like the insurance which covers 100% of your bills every time you go to a doctor. National health insurance covers 70%, right? This is all.
Source