Kururikuru!

After a catastrophic event known as “Noah’s Flood” submerges Tokyo, Kodai loses his younger sister and refuses to move on from the life he has left. He keeps to the remnants of his old routine, unable to face his loss. Then a mysterious girl named Kururi emerges from the endless sea and claims that Kodai’s home belongs to her. After they are briefly pursued by a mafia-like group, Kururi makes herself his new roommate. As the two adjust to life in a world reshaped by “Noah’s Day,” Kodai is pushed to begin moving forward.