The following version of this book was used to create this study guide: Murata, Sayaka. Earthlings. Grove Atlantic. 2020. Print. English Translation by Ginny Tapley Takemori.

The novel is narrated in the past tense by the main character, Natsuki. Natsuki was 11 and headed to the mountains of Akishna with her family for the Obon summer holiday. Natsuki always spent the summer with her large extended family, and she was excited to see her cousin, Yuu. He was 11, too, and he was her boyfriend. Yuu had always been Natsuki’s best friend, but when they were both 9 Natsuki had revealed to him that she was a magician. Her stuffed hedgehog, Piyyut, had traveled to Earth from the planet Popinpobopia when the Popinpobopian Magic Police had discovered that Earth was facing a crisis. He had come to save the planet, and he had given Natsuki magical powers to help him on his mission when she was just six. In turn, Yuu had told Natsuki that he was an alien who had been dropped off in a spaceship. One day his spaceship would return, and he would fly away. Natsuki cried at the thought and asked if she could go with him. He said she could not, so she asked him to promise to be her boyfriend until he left. In the narrative present, Natsuki and her family arrived at the Akishna house. Natsuki was delighted to see Yuu, and they prepared to spend the whole vacation together. However, Natsuki’s sister, Kise, got upset when their cousin Yota made fun of her and demanded that her parents take her home. Natsuki asked Yuu to marry her before she left. Yuu agreed, and the two kids performed a marriage ceremony in the graveyard with wire rings and signed a marriage contract.

In the second chapter, Natsuki got back home and got ready to start cram school with her teacher, Mr. Igasaki. Her mother criticized her for wearing a black shirt, then berated her in front of the neighbor and called her a useless waste of space. Natsuki agreed with her mother and apologized. She went to cram school. When Mr. Igasaki asked Natsuki to stay after class, as he frequently did, he put his hands under Natsuki’s shirt and touched her body. Mr. Igasaki left Natsuki alone for a few months, but then he asked her to stay after school. He placed a used sanitary pad on the desk and told her she had thrown it away in the bathroom incorrectly. She was incredibly disturbed and confused as to how he had known. He forced her to take off the pad she had on and put a new one on in front of him so she could practice disposing of the pad properly. She rode her bike home quickly and told her mother what had happened, but her mother beat her for having a filthy mind. After school ended, Natsuki eagerly awaited the trip to Obon and her reunion with Yuu. She went to the annual festival with Shizuka, but Shizuka’s stomach hurt and she went to the bathroom. Mr. Igasaki approached Natsuki and told her Shizuka was at his house because she felt ill. Natsuki went to his house to save Shizuka, but when she arrived the house was empty. Mr. Igasaki forced her to perform oral sex on him and made her promise to come back soon. At home, Kise told her mother that she did not want to go to Akishna. Her mother agreed, and Natsuki despaired. She spent the night wishing she could be reunited with Yuu, and in the morning she learned that her grandfather had died, and they were heading to his funeral in Akishna. Natsuki was delighted to see Yuu. She asked him to have sex with her since her mouth had died and she wanted to use her body while it still belonged to her. He agreed, and they had sex. After, Natsuki tried to kill herself, but Yuu stopped her. The adults discovered them and were horrified.

In the third chapter, time jumped ahead and Natsuki was 34 and married to Tomoya. They had met online on a website where people could find mutually beneficial arrangements. They had separate bedrooms and only lived together so that their families would leave them alone. When Tomoya got fired from his job, he asked Natsuki if they could go to Akishna to stay for a while. Yuu was living there after having lost his job. He invited them in graciously, but remained cold and distant from Natsuki.

In the fourth chapter, Natsuki remembered how she had returned home after having sex with Yuu. Mr. Igasaki called and asked her to come over for another special lesson. Her ear started to die, and the voice of Piyyut began to speak to her. He told her to go to Mr. Igasaki’s house and kill the Wicked Witch. Natsuki did as Piyyut asked. Later, she read in the newspaper that Mr. Igasaki had been murdered. Piyyut never spoke to her again.

In the fifth chapter, Natsuki and her husband stayed in the mountains with Yuu for weeks. They wanted to stay forever, but knew that their families would force them home sooner or later. Kise arrived and told Natsuki their mother wanted her to come home, and mentioned that Mr. Igasaki’s parents were still handing out leaflets about their son. Tomoya decided he wanted to become a full-blown alien, so he wanted to break human taboos. He went to Tokyo and propositioned his brother for sex. When his father found out, he chased Tomoya back to the mountains and dragged him and Natsuki back home.

In the sixth chapter, Natsuki and her husband resumed their normal lives, but then decided to abandon them and become aliens together. They retrieved Yuu and then returned to the mountains where they lived like aliens and devoted themselves to rationality and surviving off the land. A snowstorm and a landslide trapped them in the house. One night, Natsuki woke up to an attack. She fought off her attacker and killed an old man and old woman. Later, she realized it was Mr. Igasaki’s parents, who she assumed had come to kill her in revenge for their son. The trio ran out of food and decided to eat the Igasakis. After they did so, they decided to eat each other. In the end, a rescue crew arrives and vomits at the horrific scene while the trio walks out into the world in bliss.