本作改编自长冈弘树创作的现实派警察推理小说《教场》系列，首次以写实手法揭开警察学校那从未被公开的真实内幕。木村拓哉饰演冷酷无情、白发夹杂、右眼为义眼的鬼教官——风间公亲。他在被称为“未来警察的摇篮”的警察学校中，以冷峻的目光审视每一位怀抱理想而入学的学员，与他们展开一场又一场充满紧张感与心理角力的对峙。在后篇《Requiem》中，他的追查仍将持续。与此同时，毕业生们在寻找被掳走的纱罗下落的过程中，查明绑架犯计划在“第205期生的毕业典礼上制造某种事件”。

When they were middle school students, Eiji Aihara and Naohiko Bessho attended the same school and they were best friends. One day, Eiji's childhood friend Izumi Shiosaki transferred to their school. Eiji had feelings for Izumi, but he never told her how he felt. Naohiko though confessed his feelings to Izumi and they became boyfriend and girlfriend. Now, all three are first year high school students and attend the same school. There, they meet Koharu Fujimura, who begins to have feelings for Naohiko, Taichi Senami, who is a member of a band, and Mizuho Ikezawa, who is a literary girl and likes Eiji.

Misuzu Hara (Nao) works as a high school teacher and prefers to keep a distance from her students. In her past, she was raped by her best friend’s boyfriend Hayafuji after he found out she liked him. She didn't report the crime to the police and she didn't tell anyone else what happened. She still suffers from the trauma from what happened, but she continues to have a forceful relationship with Hayafuji who is now her best friend’s fiancee. One day, a rumor spreads that her student Yuki Niizuma is in a secret affair. Misuzu Hara, as his teacher, has a meeting with him to provide counseling.

高中二年级学生片切友一遵循母亲的教导，从小就以“朋友比金钱更重要”为座右铭，积极地过着学生生活。自从父母过世后，友一就一直过着贫困的生活，但他无论如何都想要和朋友一起去参加修学旅行，于是便拼命打工赚取修学旅行费。但是有一天，班上同学交上去的200万日元修学旅行费突然被偷了。在开始搜查犯人、班上的气氛变得糟糕起来后，年级第一的秀才美笠天智、有钱人家的大少爷兼气氛制造者四部诚、正义感强的刑警之女泽良宜志法、为人老实且喜欢漫画的心木友都，这些和友一关系好的同学与友一一起被绑架了。被绑走的5人醒来后，他们发现自己身处于充满谜团的“朋友游戏”的会场。随后，游戏的向导马拉布出现于毫无头绪且陷入了大慌乱状态的友一等人面前。马拉布向他们告知他们5人之中有个人欠了2000万日元，希望他们一起参加游戏来偿还债务。