It was supposed to be just a regular daily bus drive to their high school for Watanabe Sheena and her friend Yuk, but when the bus enters a thick fog, the unexpected happens and the bus gets transported to another world that seems prehistoric. With the bus driver gone, the only other passengers on the bus in this mysterious world are all high school girls: Izumi, Ayu, Kyoka, Anna and Jessica. With no cell phone or internet signal, they are completely cutoff from their world. To make things worse, they see hundreds of glowing eyes of predators at night waiting for the girls to make a mistake. How will seven high school girls survive in this treacherous place and get back safely to the real world.
(Source: MangaHelpers)

Asatte no Houkou follows the lives of Karada Iokawa, a young girl who is set to join junior high school after summer is over, and Shōko Nogami, a young woman who has just returned from studying abroad, who also happens to be the former girlfriend of Karada’s older brother.
The day Shōko returns, she is dragged by Karada to the beach with her brother and a couple of their friends since she used to know Karada’s brother Hiro several years before. After becoming irritated with Hiro for leaving her alone in the United States, she purposefully tells Karada that her ribbons are childish. This upset her greatly because she doesn’t like to be treated as a child.
Later that same day, Karada is found by Shōko praying at a shrine, wishing to become older. Amazingly, Karada’s wish becomes true and she instantly transforms into a young woman. Incidentally, Shōko then has her adulthood taken away from her and she reverts back to about eleven years old.
(Source: Wikipedia)