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" EndSectionUncomment line with "ctrl:nocaps" if you wish make CAPS key additional CTRL key.
# cp xorg.conf.new /etc/X11/xorg.conf