Runo in Japan has an interesting page for DIY men’s underwear. S/he says:

Welcome to men’s underwear gallery ‘Snake Charmer’.

Are you a guy who loves something cute?

I make lacy and fancy underwear. All for boys and cute men.
These handmade underwear and lingerie are decorated with frilled lace and ribbons.
So graceful, pretty and fancy. Not sexy.

My underwear is not for sale.
If you want to make one by yourself, I would help you at DIY page.

Runo also makes dolls. S/he’s quite a talented individual - a set of FAQs can be found here: