“after / behind” in Japanese is 後, read go, kou, ato (ご, こう, あと, うし). It is a Grade 2 Kyōiku kanji, taught in year 2 of Japanese elementary school, and appears in words such as 午後 (afternoon).
What does 後 mean?
ごはんの後で あそぶ。
Same sound, different character — the classic trap. Compare them side by side: