ATRI -My Dear Moments-

In the near future, much of the world has been forgotten at the bottom of the ocean. Natsuki Ikaruga is invited by a mysterious woman to search for a treasure in his grandmother's house. One day, he dives to the bottom of the ocean in a submarine and encounters a mysterious capsule with a girl sleeping inside. The girl was a humanoid so sophisticated that she could be mistaken for a human.

"I'll be your leg, Master!" Atri, who was supposed to be with Cathrine, has come back to Natsuki. Although she was pumped to be of assistance to her new master, she fell into the ocean while carrying him and failed at cooking… It's as if she is a piece of scrap. Atri seems to have received a very important order from Nonko and tries to remember what it is, but...

Natsuki accompanies Atri who is on her way to school. However, when they arrive, they find that most of the school is underwater. Although they managed to get into the school building, inside it was full of empty classrooms and an unexpected teacher. There, Natsuki is faced with the saddening reality of the lives of the people who remained in their town.

Natsuki sets his heart on creating a tidal power generator that utilizes the ebb and flow of the ocean's tides. As they are working, Natsuki and Ryuuji exchange heated opinions over how the generator should be built. Atri intervenes and the two guys become closer friends. Meanwhile, a suspicious-looking character peeks at them from outside of the school....

Atri, who was supposed to be with Cathrine, has come back to Natsuki. Although she was pumped to be of assistance to her new master, she fell into the ocean while carrying him and failed at cooking.

Natsuki's life experiences a big shift after becoming a teacher and starting a salvaging service. Rumors of a school lit with electricity attracts new students, and activities around the school regain a sense of liveliness.

Date With a Robot Girl

Natsuki has been acting strange and seems to have his head in the clouds through everything he does. After being interrogated by Minamo and the others, he reluctantly confesses to them that he kissed Atri in the ocean.

Natsuki happens to see Atri's log that was left open. What was written there was an emotionless record of how she carried out her actions to fulfill Natsuki's desires. Natsuki instinctively rejects Atri and is no longer able to trust anything.

Eventually When the Rain Stops

The End of Summer and Your Sound

Atri's last order that was given to her by the capsule was to go to Eden. However, Natsuki and the rest are perplexed by the incomplete set of instructions and don’t know where to even start looking.

Only three days remain. Atri decides to become a part of Eden's system, and the clock ticks on for Natsuki who decides to spend his life looking for a way to save Atri.