Magazines for & about cross-dressing boys and even healthy sex guides for traps are pretty common in Japan. One of these mags, Oto★Nyan, apparently wanted to save some traps the potential embarrassment of buying girly underwear in stores by adding a bra and panty to their latest issue as Sankaku Complex reports…
Issue 6 of Oto★Nyan comes with a bra and pantsu for boys, randomly in either pink, green or purple horizontal stripes, in addition to the usual art, comics and articles addressing the finer of points of femininity for non-females. The precise size is not specified, but it is said to be “highly elasticated,” and so will presumably fit a wide variety of effete male frames.