BUR #13904 has been rejected.
create alias chen -> chen_(touhou)
create alias chen_(cat) -> chen_(cat)_(touhou)
remove alias chen -> chen_(touhou)
deprecate chen
Incredibly ambiguous name, should be qualified.
EDIT: Just saw this was previously discussed at forum #184809. While I don't think some of the other single name Touhou characters need qualifiers, I still stand by this BUR as Chen is a very common Chinese surname and shouldn't be an unqualified tag.
Updated