Invoking Xorg after running kbd jp (or jp.swapctrlcaps), almost keymaps are OK. But pressing ], the character \ is entered. The case of } and | are alike.
Workaround:
# X -configure
Section "InputDevice"
Identifier "Keyboard0"
Driver "kbd"
Option "CoreKeyboard"
Option "XkbRules" "xorg"
Option "XkbModel" "jp106"
Option "XkbLayout" "jp"
# Option "XkbVariant" ",qwerty"
# Option "XkbOptions" "grp:menu_toggle,grp_led:scroll"
# Option "XkbOptions" "ctrl:nocaps"
EndSection
Uncomment line with "ctrl:nocaps" if you wish make CAPS key additional CTRL key.# cp xorg.conf.new /etc/X11/xorg.conf