SQL> CREATE TABLE JAP_NM_TEST
  2  (
  3    KANJI_NM  VARCHAR2(500 BYTE),
  4    KANA_NM   VARCHAR2(500 BYTE)
  5  );

Table created.

SQL> insert into JAP_NM_TEST values('ﾀﾅｶ ﾄﾓﾅﾘ','ﾀﾅｶ ﾄﾓﾅﾘ');

1 row created.

SQL> commit;

Commit complete.

SQL> select * from JAP_NM_TEST;

KANJI_NM	KANA_NM
------------ ------------
ﾀﾅｶ ﾄﾓﾅﾘ       ﾀﾅｶ ﾄﾓﾅﾘ


SQL> -- What if when we select this data is xml
SQL> -- The Data get corroupt
SQL> SELECT (XMLFOREST (XMLELEMENT ("names", XMLELEMENT ("KanjiNm", a.kanji_nm)) AS "NM").getclobval ()) AS SQLDATA
  2    FROM jap_nm_test a;

SQLDATA
--------------------------------------------------------------------------------
<NM><names><KanjiNm>・ｽﾅｶ ・ｽ・ｽ</KanjiNm></names></NM>