Karabiner　settings

private.xml

<?xml version="1.0"?>
<root>
  <item>
    <name>ろ to ~</name>
    <identifier>private.change_RO_to_BACKQUOTE</identifier>
    <autogen>__KeyToKey__ KeyCode::JIS_UNDERSCORE, KeyCode::BACKQUOTE</autogen>
  </item>

  <item>
    <name>VK_CHANGE_INPUTSOURCE_CHINESE_SIMPLIFIED</name>
    <identifier>private.VK_CHANGE_INPUTSOURCE_CHINESE_SIMPLIFIED</identifier>
    <autogen>__KeyToKey__ KeyCode::JIS_KANA, KeyCode::VK_CHANGE_INPUTSOURCE_CHINESE_SIMPLIFIED</autogen>
  </item>

  <item>
    <name>VK_CHANGE_INPUTSOURCE_JAPANESE</name>
    <identifier>private.VK_CHANGE_INPUTSOURCE_JAPANESE</identifier>
    <autogen>__KeyToKey__ KeyCode::JIS_BRACKET_RIGHT, KeyCode::JIS_KANA</autogen>
  </item>
</root>