I distinctly remember learning about this in primary school, when I was five years old. :)

Regarding the video: Gold and copper can often be found in the same ores. So it makes perfect sense that combining the kanji for “gold” and “the same” creates the kanji for “copper”. :)

Regarding the video: Gold and copper can often be found in the same ores. So it makes perfect sense that combining the kanji for “gold” and “the same” equals “copper”. :)