Gokusen/ごくせん Series by Kozueko Morimoto, Maria Fransiska

Fresh out of college, Kumiko "Yankumi" Yamaguchi becomes a math teacher at an all-boys high school. Unfortunately for her, she's assigned by the school board as the homeroom teacher for class 3-D, which happens to be the class of delinquent students. When the class attempts to make a living hell out of Yankumi's career, they fail as her persistence and aggression gain her respect... moreFresh out of college, Kumiko "Yankumi" Yamaguchi becomes a math teacher at an all-boys high school. Unfortunately for her, she's assigned by the school board as the homeroom teacher for class 3-D, which happens to be the class of delinquent students. When the class attempts to make a living hell out of Yankumi's career, they fail as her persistence and aggression gain her respect. However, little does anyone in the school know that Yankumi is actually heir to the Kuroda Ikka - one of Tokyo's most powerful yakuza clans. less

Yankumi bersama keluarga Kuroda akhirnya merangsek markas Salib Hitam. Walau kalah jumlah, Yankumi berusaha menyelamatkan Bu Fujiwara. Masalahnya, Bu Fujiwara menganggap Kak Kyo sebagai Ksatria Penyelamat! Yankumi berusaha menyadarkan Bu Fujiwara dari ilusinya, tapi Bu Fujiwara tak terpengaruh. Apa yang harus dikatakan Yankumi, ya?