Nigatsu no Shosha: Zettai Gokaku no Kyoshitsu

Kuroki Kurodo was an extremely competent teacher at a prestigious cram school for the middle school entrance exam. He begins to work as the director of a cram school with poor performance. He declares that the students here will pass their middle school examinations. Kurodo states a cram school is a service business and the school is a place to sell children's future to parents.
(Source: AsianWiki)
~~ Adapted from the manga series "Nigatsu no Shosha: Zettai Gokaku no Kyoshitsu" (二月の勝者-絶対合格の教室-) by Takase Shiho (高瀬志帆).