Hi Perrine,
You can see the revision history for the tags here:
https://www.behindthename.com/tags/history.php?name=sachiko
It doesn't seem like they were ever added for Sachiko. If you are sure you remember adding them, then perhaps there was an error message upon saving that you didn't notice. Or perhaps you forgot to push the save button altogether after adding the category (I have done this in the past).
Mike