The Japanese phrase translates literally to "I told you to put on a condom."

"Gomu o tsukete to iimashita yo" is a textbook example of how a localized, intimate, and grammatically polite phrase can travel across borders to become a cross-cultural internet artifact. To a linguist, it is an exercise in the contrast of polite Japanese grammar and raw subject matter. To a sociologist, it reflects real-world dynamics of safe-sex communication in Japan. And to the internet at large, it remains a memorable, frequently quoted line that captures the distinct, often transgressive humor of global anime culture.

A non-native speaker wanted to say: “I told you to put on an eraser (as in pencil eraser).” They were teaching a child to correct a mistake on paper. But instead of using the word keshigomu (消しゴム = eraser), they said just gomu . Then, instead of using the verb kakeru (to rub/erase), they used tsukeru (to attach).