Students from Hosho Academy High School were aboard a plane when it crash lands under mysterious circumstances. The heroine, Oribe Mutsumi and her classmates wash ashore on an island. The surviving passengers decide to wait for help to come, but the island turns out to be inhabited by giant insects! Mutsumi wakes up on a beach and finds her classmate Matsuo Ayumi. They use their wits to procure food. Believing that help will come in three days, they decide to endure until then.

[Source: Crunchyroll]

After an airplane crash during a school trip, Oribe Mutsumi and her classmates were stranded on a seemingly deserted island. Mutsumi found the other survivors, and used her wilderness knowledge to help them. She expects that they will be rescued in about three days, which doesn't seem so long to endure. However, she didn't account for the fact that the island is populated with gigantic killer insects. Her knowledge of butterflies, wasps, and more may be the only thing that will help any of her classmates survive to be rescued!

[Source: MangaHelpers]