More than 10 years have passed since the birth of a transfer device from the earth to another world. Satomi Kakeru is a high school student with survival knowledge and skills instilled in her by her grandfather who lives in the mountains. In order to participate in training to become an adventurer, Kakeru transferred to a different world with 100 adventurer applicants of the same generation, but immediately after that, the portal that connected the earth and the different world disappeared. Put it away...! ! With the way back to Earth blocked, a dangerous life of survival begins on an uninhabited island in another world! !