Cutaway pictures are the best pictures.
I wish I could find them easier!
That seems like a lot less padding than I’ve come to expect from European armor.
As the saying goes, “Japanese swords were made to defeat armor; European armor was made to defeat swords.” There’s a different overall emphasis - Japanese armor is meant to protect one against everything up until the most brutal part of the melee, where everything is resolved - European armor is meant to protect against everything, and then some. The difference means that late European armor is ungodly heavy (~30kg) in comparison to late Japanese armor (~15kg, not to be confused with earlier, heavier O-Yoroi which clocks in at closer to 25kg), and needs a hell of a lot of padding to avoid ending up looking raw and red under all that metal!
“Japanese swords were made to defeat armor
Who says that? That sounds like bullshit, straight-edged swords (especially the late medieval ones with extra-strong tips) are much better at dealing with armor than curved swords.
Rather than being an absolute comparison of the ability to pierce armor, the saying is meant to reflect a difference in priorities and development.