Japan travels with a group. I told two friends to travel to Japan, and today I asked many travel agencies that there are no triple rooms or single rooms. You can only spell one with strangers.

It is necessary to make up the difference. It's basically the same wherever you go, except that you make up the difference a little more. Generally speaking, travel agencies will book double rooms. Unless you sign up for an advanced tour group such as a private tailor, the package tour is usually a standard room, so if there is uneven distribution, those who live alone will definitely make up the difference, even if you change travel agencies now. The problem is that this is a bit too much for 3K. I don't know what kind of hotel you are staying in.