When God Says No Two Friends Bounded Together by the Promise, Never to Let One Another Go

When Rie decided to walk into the sea, she was saved by a mysterious girl named Ryoka. Through her, Rie rediscovered a new purpose in life, and a passionate friendship. But Ryoka had her own dark past, and their friendship may not be able to withstand the secrets between them. Will either girl survive, when they've put their faith in each other?