和歌山県の 動物園に、コウテイペンギンが 十九羽 います。
一羽だけ、まだ 名前が 決まって いませんでした。
この ペンギンの 番号は 四十四です。
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.