I don't have enough information to say exactly who Miu Sakamoto is in this context. They could be an author, a storyteller, or someone involved in creating this 'never ending story'.
Ryoma can be seen as the laid - back prodigy. He has a natural talent for tennis but doesn't flaunt it as much as Atobe. His cool - headedness in high - pressure situations is a key characteristic. Atobe is depicted as the showy and self - assured player. He loves to put on a show during matches and has a certain elegance in his playing style. In fanfiction, their different personalities lead to a lot of clashes at first, but also to a growing understanding and connection as the story progresses.
Sakamoto and Kouta are likely characters that fans have created a relationship for in fanfiction. They could be original characters, or perhaps characters from an existing series that the fanfiction writer has chosen to pair up in a new and creative way.
The 'Sakamoto Days' novel is mainly about a former top - tier assassin named Sakamoto who has retired and become a fat, unassuming man. But his past catches up with him, and he gets dragged back into the dangerous world of assassins. It's full of action, interesting characters, and unique fight scenes.
Ryoma would be calm and collected as always, but with a newfound sense of responsibility. He'd be more cautious and less impulsive. Sakuno would be very gentle and motherly. She'd be full of love and patience, always there to comfort the baby. Ryoma might be a bit more reserved in showing his emotions towards the baby in public, but in private, he'd be very affectionate.
In the fanfiction, Ryoma might be jealous if he notices Sakuno paying more attention to another male character. He could be too proud to admit it at first, but his actions, like being more aggressive in tennis matches or avoiding Sakuno, would give it away. Eventually, he might confess his jealousy and feelings for her.
The main character is Sakamoto, of course. He's the ex - assassin. And there are other assassins who play important roles as well, like Shin. They interact with Sakamoto in various ways, either as opponents or sometimes as reluctant allies.
Potentially, she would interact with teachers at Rikkadai. Maybe there's a strict tennis coach who has high expectations but also sees great potential in Fem Ryoma. And then there are the classmates, some of whom might be jealous of her tennis talent while others are friendly and inclusive. There could also be rivals from other schools when Rikkadai has inter - school tennis events.
In this fanfiction, Sakuno could be the jealous one. Suppose a new girl joins the tennis club and she seems to have her eyes on Ryoma. Sakuno might start to feel insecure and try to be around Ryoma more often. She could also try to improve her own tennis knowledge to be more involved in his world. For example, she studies the different techniques and strategies just to have more to talk about with Ryoma.