Mizuki Koichi (voiced by Kento Ito) is a recognized tall man. His 180cm height makes him the most conspicuous person wherever he is. By chance, Koichi was summoned to the Giant Country by a man named Caius (voiced by Tomoki Ono). Caius, who is 250cm tall, made a violent statement as soon as he saw Koichi, hoping that Koichi could become his bride and give birth to offspring for him. In this way, Koichi began his new life in the Giant Country. Medina (voiced by Tsuyoshi Fujimoto) was Caius's original fiancée, but she was robbed of the position of queen by Koichi who showed up halfway, so she was always full of hostility towards Koichi. The Giant Country has not always been in a peaceful state. Barrow (voiced by Masatomo Nakazawa) and Bailey (voiced by Yusuke Shirai) from the neighboring Orc Country have been eyeing it covetously.