Kafka on the Shore question

I think I've figured it out. That white blob really is referencing a symbolism he used in his novel "The Wind-Up Bird Chronicle." I was just reading a few pages of the novel where it mentions a squishy blob as a symbol for death. This is from p. 20 of the Vintage edition:

"...the lump of death. I'm sure there must be something like that. Something round and squishy, like a softball, with a hard little core of dead nerves. I want to take it out of a dead person and cut it open and look inside. I always wonder what it's like. Maybe it's all hard, like toothpaste dried up inside the tube. That's it, don't you think? No, don't answer. It's squishy on the outside, and the deeper you go inside, the harder it gets. I want to cut open the skin and take out the squishy stuff, use a scalpel and some kind of spatula to get through it, and the closer you get to the center, the harder the squishy stuff gets, until you reach this tiny core. It's sooo tiny, like a tiny ball bearing, and really hard. I t must be like that, don't you think?"

I've been wondering lately if it's something from Japanese mythology that I don't have references for. Kind of like Noh-face in "Spirited Away" or something. They do have a bundle of odd creatures in Japanese mythology, so anything is possible.

What I found more strange was Johnny Walker! A scary and evil character that wasn't really explained within the plot. He turned out to be Kafka'a father, but then there is confusion when towards the end he is on the lake and has his eyes pecked out by the boy named crow... then it was simply left and there were no implications left from the flute being played...

Just a wild thought. Murakimi's symbolism is often about war, and the atomic bomb has been in other works. Perhaps the white blob is the musroom cloud, or the light from the Abomb explosion.