Tetsuya works hard as a taxi driver, and enjoys anime, manga and games during his private time. While he is satisfied with his current situation, he can’t help but feel a bit lonely not having anyone around with whom to share his hobbies.
One day, he picked up a female passenger and noticed that she had a keychain of a character from an old anime he loved. They chatted happily about anime during the ride and she gave him a business card when she got off. She worked at the anime song bar Blue Comet, a place where otaku like him can gather and chat in a relaxed atmosphere. He was somewhat interested and decided to pay it a visit. Meeting others who have the same hobbies as him, his daily life began to gradually change.
Shukugawa Meguri is afflicted with an illness called the “Oumon” disease. At this point in time, nobody knows its cause, and there’s no real treatment for it yet. The only option with a slight chance of success, is to undergo a heart transplantation. But finding a compatible heart is something that can be compared with a miracle. For that purpose Meguri’s sister, Ria, was actually born as a designer baby. So that her heart could be used “like a spare”.
This is the story about two sisters, the youngest born for the sake of the eldest. Other than their family, only Ria’s best friend Ryuuji knows about their secret. Her resolve wavers during the little time they have left. What will be the conclusion at the end of these emotional moments?