Agree! I think in this case these drawing have a lot of implementation details. It is actually the pattern table, the palette etc.
On the BG Planning Sheet, 年 月 日 mean Year Month Day -- for indicating the date. 時 分 are Hour Minutes -- for indicating the time. デザイナー means Designer and プログラマー means Programmer.
Oddly, the last page seems to be a mirror image, and it's quite difficult to read the text. However, it appears to be for designing an individual sprite. There is a field labelled キャラクター (Character) along with Date and Memo fields.