How to make an image without mask/with only the main thing and no white automatic rectangle-ness?

[Venus]

My website is japanaddicts.wordpress.com and I want a logo for it with only a letter J. Many websites have logos that only feature one thing and are not square, for example, some logos are in circle, some are letters, like A, etc.

I make an image with 'no background', but white is added automatically in my programme. It saves a mask or something.

Why cannot I make an image with only a major thing and no square made out of it?

Please help. I can only upload .jpg or .png pictures.

[Robert G]

What program are using to make this? You want a transparent background, not no background.