Eleven-year-old Natsuki is different. She doesn’t fit in. She is an outsider in her own family. Her cousin Yuu is the only one she can relate to. Natsuki and Yuu spend their summer every year on the wild mountains of Nagano, at their grandparents’ place.
Natsuki is convinced her stuffed animal, Piyyut, is from another planet. Yuu thinks he is an alien himself. They spend their summers dreaming of other worlds, exploring and trying to survive in a world they feel they do not belong in. When a horrible sequence of events separates them from each other, they promise that no matter what, they will survive. 
Now, years later, Natsuki is an adult, and she is married. Her husband is different too. They have a different arrangement that works for them, but it goes against societal expectations. Natsuki tries hard to be normal, but society and her family keep pressuring her to have a child. She and her husband both suffer from horrible childhood traumas, and they cannot function in the usual society or meet the demands of that society. They want to be free from the shackles of society, so they flee to the mountains of Nagano. But Yuu is there. And Yuu is like them. Someone who doesn’t fit in but tries hard to. Natsuki prepares herself to meet Yuu again, but the shadows of her past follow her every step. 

This is an insanely thought-provoking book. The author has used horrifying graphic details and taboos to portray her philosophy artistically. Through the character Natsuki, the author states that society is a machine and humans are the cogs in it. Playing by the same rules day after day, year after year. Humans making more humans, humans working for other humans—it’s an endless cycle. But there are cogs that don’t quite work, and society is never kind to them. A neurodivergent person, a queer person, or a person with mental illness cannot function according to societal standards and demands. There is no absolute freedom. Either you try to fit in your whole life or you strive for a freedom where you become something worse than a monster. There is no winning. 
This book is disturbing and complex. The characters go through horrible traumas and act out some awful taboos. But all are necessary for the message the author intends to send. Truly an intriguing book. 

-Ariana