Is domain monopoly possible?

Yes, and I will do it personally
..and I know how to speak Japanese as well but can't write..

This can happen if for example you do not register the domain your self (Using your credit card or payment information). For example, when I was just starting out, I needed hosting and I used a local hosting company. However, you had to select the hosting package you want and the domain and then send it to them. They would register it on your behalf and set up your hosting account.

When it expired, you had to send money to them and they would renew it for you. So you had no control over it.

Now that was 2006 and i finally gave up the domain.

What happens now, even for "some" international registrors is that when your domain expires and you have not yet renewed it, they will (Not all registrars) redirect it to any webpage they desire, and it make sense that local registrars will redirect it to another local company, though this is not good business practice.

The only way you can minimizes this is to always register the domain using your own payment details where by you have full control over renewal and extensions. You should also use professional companies. I believe there are many over there in Philippines.

Lastly, It could have been hacked as others have pointed out. I have seen many famous sites hacked and redirected to other sites. Usually, the owner may not know that this is happening until the damage has been done.

Would you do that if you are in Japan, Korea, Russia, Germany, or other non-English speaking countries? There are reasons why country TLDs are created but the problem is the security issues.