Last Game Series by Shinobu Amano

He's rich, he's smart, girls gather around him all the time, and he has always gotten first place on his exams... well, until Kujou transferred in his primary school class. She was quiet, plain, and poor, yet not once has she failed at beating Yanagi, both in academics and sports! Yanagi has made it his life goal to defeat this girl Kujou, and ten years later, as they enter high school, he just might finally win! This is the story of their last game.

He's rich, he's smart, girls gather around him all the time, and he has always gotten first place on his exams... well, until Kujou transferred in his primary school class. She was quiet, plain, and poor, yet not once has she failed at beating Yanagi, both in academics and sports! Yanagi has made it his life goal to defeat this girl Kujou, and ten years later, as they enter high school, he just might finally win! This is the story of their last game.

He's rich, he's smart, girls gather around him all the time, and he has always gotten first place on his exams... well, until Kujou transferred in his primary school class. She was quiet, plain, and poor, yet not once has she failed at beating Yanagi, both in academics and sports! Yanagi has made it his life goal to defeat this girl Kujou, and ten years later, as they enter high school, he just might finally win! This is the story of their last game.

天文部で新歓合宿へ行くことになった九条と柳。事故キスしたことを意識しまくる柳をよそに、九条は無防備な態度ばかりで…。天体観測に向かう途中、柳は九条の気持ちを確かめようとするが、突然の雨で遭難して…一夜をともに!? 2013年1月刊。