The story begins with Souko telling his mother through a letter about his condition. He was telling her that he had quit his position as ‘Assistant Chief of Data Management, General Affairs Division’ of the Palace of the Jade Emperor. It was that day that he became a member of the Western Army, the First Unit of Heaven.
Souko was looking for Field Marshal Tenpou. As he opened the door to Tenpou's room, a pile of books fell on him and he saw Kenren and Tenpou arguing about the books, causing Souko to think that maybe he had entered the wrong room.
After meeting his new superiors, Kenren brought him to his quarters where Souko met his roommate Rihaku. Kenren decided to leave the rest to Rihaku, but noticed that Jyouei, Rikuou and Yuutetsu were looking at them. Kenren ordered them to go back for training. Souko then noticed a flower beside him and asked if it was Rihaku’s. He learned that it was a flower from the lower world called "Tenjiku Botan" or Dahlia. Souko then stated to himself that 'there are no ants in Heaven.'
Some time later, their training began. Souko introduced himself to Tenpou and they began their basic training. But it was not the training that Souko had expected. Instead, Tenpou had them play baseball as training, basing it on a manga he had been reading. While the rest were playing, Kenren was telling Tenpou that they didn't need to recruit another member. Tenpou responded that it was actually Eizen's decision, the reason being that it was difficult to create formations with 13 members. In addition, '13' is an unlucky number in the lower world.
All of a sudden, there were orders for the First Unit, causing everyone, to turn serious, including Tenpou, who according to Souko, was like an entirely different person. The announcement was for them to go down to the lower world.
It was the first time that Souko saw how blue the sky was. The First Unit encountered a strange creature, and so part of the group separated and started to attack. While Souko was observing them through binoculars, it was also the first time Souko saw an ant. A while later, Tenpou's group runs out of anesthetic bullets. Souko volunteered to ammo to them, and he did not fail.
Souko responded "It's really... awesome!"
Kenren told him that there was more to see that was even beautiful than the sky, like the twlight sky, and the morning sunrise.
At the end of the chapter, Tenpou finally remembers Souko's name. From that day forward, Souko became one of the ants of Heaven.