The origin of a hiragana む is 武. 武者（musha) and 武士(bushi) mean samurai, but the meaning wasn't so important when developing Japanese letters from Chinese characters. 無 is also む which means nothing. In one of Nishida Kitaro's books, he wrote that 無 is love when he compared with the western concept. I agree.
無 holds everyting else.
Talking of love, I fell in love with the letter Iida Kazuko Sensei wrote for one of Basho poems. I asked her to draw that particular む in the same way. She brushstroke in red ink right then and there a few times and gave me that as you see above photo. It is just a む. But it has characters. Don't you think? They are, in fact, two kanji characters, and the character, in other sense, is nothingness but in a samurai way. We call this kind of arts, playful. Yes! Playing is the key. You can interpret your own way, and choose your own brushstrokes. I've uploaded kana shodo blog spots again because my past "Kana Shodo" blog spot is the most popular so far. Thank you for appreciating our traditional art!
Below is my Japanese blog, and the second photo shows the old pond and a frog poem by Basho in which that same む appeared. http://keiko-booksandtalksfromlosangeles.blogspot.com/2010/12/blog-post.html