Okay, so here goes the plot synopsis.
Summary:
15-year-old Kanagawa Sabaki doesn't have the best relationship with her family. Her mother is the CEO of a major corporation and has high expectations for her future. However, from a young age, Sabaki-chan fell in love with Go (the board game; popular in East Asia) and wanted to be a professional go player. Her father supported Sabaki-chan's goals and her mother was vehemently opposed to it, and this actually resulted in their family almost getting divorced because they fought so much over it. Unfortunately, the Kdrama traffic accident happened the Sabaki-chan's father was hit by a car and died, which left Sabaki-chan's mother devastated. In the end, the mother allowed Sabaki to travel to Tokyo to attend
a professional go player school.
Sabaki-chan has and elder sister named Fuyuri (26 years old) who has always been a huge role model to Sabaki. Fuyuri was living in Tokyo as a PhD student at Tokyo University, and she allowed her younger sister to move in with her. Together, the two sisters lived together, except that Fuyuri started dating one of the eccentric assistant professors at Tokyo University named Asato-san. Pretty soon all three of them starting living together in the same appartment.
At first Sabaki-chan did not like Asato-san, since he was weird, messy, and way too nerdy, and basically he looked like a crazy man who never slept, but eventually over time she grew to accept him more. One of Asato-san's major things was that he was struggling to obtain grant funding to support his research (basically he's a failed researcher), and he spends all of his time writing grant applications to fund his science. Any time that Sabaki-chan would wake up, Asato-san would always be awake no matter the hour (3am, 4am 6am), constantly typing away with crumpled up sheets of paper with bad ideas. Sometimes, Asato-san would talk to her, and Sabaki-chan would study go on a go board (placing black and white stones on the board) nearby while he typed away late into the night.
Asato-san got engaged and married to Fuyuri (the elder sister) relatively quickly, and Sabaki-chan was superficially very happy for them....
...except also not, because eventually Sabaki-chan realized that she had feelings for her brother-in-law, even though he was nearly ten years older than her (jail alert! jail alert!). Obviously, any kind of relationship was totally impossible, and it Sabaki-chan thought it would be totally wrong to go after her sister's husband.
The story ends with Sabaki-chan attempting to take the examinations to become a professional go player (1 dan professional). At seventeen years old, she fails her first attempt at this exam, and she is faced with the decision of whether she should continue struggling and trying to become a professional go player (to take the exam again next year), or if she should give up figure out what to do with her life.
She's not financially independent (has no income / job / resume), and thinks about going to work part-time in a convenience store. Her sister and brother-in-law and happy to keep allow her to keep living with them (for now), but Sabaki-chan struggles really hard over this decision, because she has unrequited feelings for Asato-san.
The story ends with Sabaki-chan looking over a bridge all by herself under the Tokyo night sky on her eighteen birthday.
The end!