bringing parents...

What is the procedure for bringing parents?

How long they can stay with us? Can they stay with us as long as we stay in Tokyo.

If any one of you know the information, please reply

do you mean you are living in Japan and want to bring your parents in to live with you?

If you mean they are not in Japan and not Japanese nationals and you wish to bring them to Japan to live with you.

They would need to qualify for a visa just like everyone else.

A dependent visa would not work because a dependent visa is based on spouses and/or children of yours.
A dependent visa does not include parents, siblings or any other relatives.

Your parents would have to come over on a tourist visa (if they need one) but usually these can be from 14 days - 90 days depending on their nationality.

so, you mean they can come only by tourist visa and they can stay only 90 days...can this be extended after they come there? If yes, how long can it be?

Depends on their nationality. Some can extend for another 90 days, many cannot.