5 of the 7 chapters are interconnected short story about sisters Midori and Minae.
Chapter 1: I Can't Tell Anyone. Midori a Christmas Gake girl feeling unfulfilled in life and love, haunted by the memory of her cousin and the games they used to play, now have to deal with his return, and his impending marriage to someone else.
Chapter 2. I Won't Tell Anyone. Midori's younger sister Minae is left to deal with the Midori's decision from Chapter 1, and she's not happy about the turn of the events.
Chapter 3. Everything Under One Sky. Minae has always want to escape her small town life. She wants to go to the big city and live her life and not to the expectation of her famiy. Unexpectedly, she founds love with the most unlikely man.
Chapter 4. I Still Can't Tell.
It's the night before Midori's wedding to Seiji (also the day of Minae's final), and Midori tries to explain why she broke off her relationship with her ex-boyfriend.
Chapter 5. I Want to Tell Someone.
Minae found out about Midori's pregnancy, and the date just doesn't add up. She still really haven't accept Midori's selfish act. But Midori finally explain her decision to her sister.
Chapter 6 & 7 deals with Tsugumi and Mei. As far as I can tell, a completely unrelated storyline.
One cultural note regarding Midori and Minae's story. Midori and Minae don't appear to have brothers. This means in order for their family name to continue, one of their husband will have to be adapted into the family and carry their surname.
This is why Minae is so pissed off at her older sister in Chapter 2. Everyone is fully expected Midori's boyfriend to come to an agreement and be adapted into the family (he's the second son, and has an older brother, so the burden of carrying on his family's name isn't on him). When Midori decided to marry Seiji, that mooted the point, since he's expected to inherite. Yes, they're first cousin, but apparently in Japan, that's legal.
