I would suggest just going to bicCamera, yodobashi camera and try some iems there. Easier to find and also a
I found it hard as hell to find e-earphone the first time.
Fujiya avic in nakano (where the show is) has used iems for good prices. Also a quiet listening station outside the shop with many iems.
Back to the show discussion. I have bought my son aged 2-3 several times, he is quite chilled and likes meeting the other head-fiers. If you put some on ears...