There was an alias for khanshin => teddy_(khanshin).
If we just left it like that, then anything in the future tagged as khanshin or teddy_(khanshin) would end up with the old tag (teddy_(khanshin)).

The correct resolution is to remove the pre-existing alias and create two new aliases as follows:
khanshin => teddypocky
teddy_(khanshin) => teddypocky

This way, anything tagged with either of the old tags will end up with the correct tag. *Done*