Kasei Zombie

Kanon, a shy high school girl, finally works up the courage to confess to her upperclassman Akiyama and goes on a date with him to see a movie he wanted to see, titled 'Kasei Zombie.' While she is in the bathroom, suddenly an earthquake occurs and she is trapped. When she finally manages to escape, she discovers that Takadanobaba is overrun with zombies and has been blockaded off. Then, she meets a man in a blue helmet who fights zombies with a bat. Source: ANN