WITH T1 AS(
SELECT 1 SEQ , '홍길동' AS NM FROM DUAL UNION ALL
SELECT 2 SEQ , '김콩쥐' AS NM FROM DUAL UNION ALL
SELECT 3 SEQ , '김팥쥐' AS NM FROM DUAL UNION ALL
SELECT 4 SEQ , '이익훈' AS NM FROM DUAL UNION ALL
SELECT 5 SEQ , '신데렐라' AS NM FROM DUAL 
), T2 AS (
SELECT 1 SEQ , '수학공부' AS DSC  ,'영어공부' PLAN  FROM DUAL UNION ALL
SELECT 3 SEQ , '문학공부' AS DSC  , ''         FROM DUAL UNION ALL
SELECT 4 SEQ , '물리공부' AS DSC  , '국사공부'  FROM DUAL 
)

SELECT T1.SEQ , T1.NM , T2.DSC , T2.PLAN 
FROM T1 LEFT OUTER JOIN T2
ON T1.SEQ = T2.SEQ
ORDER BY T1.SEQ

외부 조인 으로 T1 table 기준으로 작성하면 됩니다.

WITH T1 AS(
SELECT 1 NO , '홍길동' AS NAME FROM DUAL UNION ALL
SELECT 2 NO , '김콩쥐' AS NAME FROM DUAL UNION ALL
SELECT 3 NO , '김팥쥐' AS NAME FROM DUAL UNION ALL
SELECT 4 NO , '이익훈' AS NAME FROM DUAL UNION ALL
SELECT 5 NO , '신데렐라' AS NAME FROM DUAL),
T2 AS (
SELECT 1 NO , '수학공부' AS BB  ,'영어공부' AS CC  FROM DUAL UNION ALL
SELECT 3 NO , '문학공부' AS BB  , ''    AS CC     FROM DUAL UNION ALL
SELECT 4 NO , '물리공부' AS BB  , '국사공부' AS CC  FROM DUAL)

select a.no "학번", a.name "이름" , b.bb "내용" , b.cc "계획"
from t1 a , t2 b
where a.no = b.no(+)
order by 1;