The Act of the Establishment of Juvenile Reformatory Schools and Enforcement of Education Article 73

Students may have interviews with their family and friends. However, if deemed harmful to the enforcement of correctional education or student learning, the interviews may be prohibited or restrained. Regulations governing student interviews shall be prescribed by the Ministry of Justice.Students may send and receive letters. The Reformatory School may also review the letters. In the event of the proviso of the preceding paragraph, if the letter is sent by a Student, the letter may be sent after the Institution explains the reasons and deletes the content upon his/her consent; if the letter is received by a Student, he/she letter may be delivered to the Student after the Institution explains the reasons and deletes the content upon his/her consent. Where a Student refuses to delete the content, the student may be prohibited to sent or receive such a letter.
中文原文 少年矯正學校設置及教育實施通則第73條
學生得接見親友。
但有妨害矯正教育之實施或學生之學習者,得禁止或限制之;學生接見規則,由法務部定之。
學生得發、受書信。
矯正學校並得檢閱之,如認有前項但書情形,學生發信者,得述明理由並經其同意刪除後再行發出;學生受信者,得述明理由並經其同意刪除再交學生收受;學生不同意刪除者,得禁止其發、受該書信。

English translation for reference only; the Chinese text prevails. Not legal advice.