“mirror” in Japanese is 鏡, read kyou, kagami (きょう, かがみ). It is a Grade 4 Kyōiku kanji, taught in year 4 of Japanese elementary school, and appears in words such as 鏡台 (dressing table).
What does 鏡 mean?
鏡で顔を見る。
Same sound, different character — the classic trap. Compare them side by side: