So apparently this is actually the cover page of the official strategy guide book for the PS2 game "魔法先生ネギま！ 1時間目 お子ちゃま先生は魔法使い！ (Mahou Sensei Negima! 1-Jikanme ~Okochama Sensei wa Mahou Tsukai!~)" by KONAMI. Someone just added a black box at the top left which blocked out 講談社 (Kodansha).

Since this is an official strategy guide book for one of the Mahou Sensei Negima! games and since the art style is pretty much identical to Akamatsu Ken's art style, I'll tag it accordingly so. I apologise if I used the wrong tags.