空 を とぶ アンテナ の 実けん が 日本 で 始まりました。
米国 から 太平洋 を こえて、日本 に とう着 しました。
でんぱ は 高知県 の きょく と つながります。
Why six school grades, and not N5–N1?
Because that is how Japanese children learn to read. Japan's Ministry of Education fixes exactly which character belongs to which grade — so "grade 3" is a boundary you can verify, not a feeling. Every article here is machine-checked: if a single character sits above its grade, it is not published.
The result: you never hit a character you have not learned. That is the whole reason this product exists.