Sweet Punishment: I'm the Guard's Personal Pet

In the near future, Hina Saotome is accused of embezzling millions of dollars while working as a treasurer for a large multinational company. The sentence has been passed, she will be in prison for one year. Her boyfriend Yakuma can't believe his eyes.

At the prison, she falls under the spell of the chief security guard, Aki Myoujin. He calls her 3,077, his number from now on. Hina finds him elegant, but he is very sadistic.

The only woman in this prison, Hina discovers a brutal world where the slightest deviation is punished. But she finds an ally, a mysterious and charismatic prisoner named Higa. He is in prison for mafia crimes, but seems extremely calm and composed. He does not hesitate to intervene between Hina and the other prisoners who want to harm her.