As of now, Uta is indeed alive. The story hasn't depicted anything otherwise. Maybe there'll be changes in the future, but for now, Uta's part in the manga continues with them being alive.
Their relationship could start with Uta being initially distrustful of Luffy. After all, Luffy is a pirate and Uta has her own ideas about pirates. But as she sees Luffy's pure heart and his determination to protect his friends and pursue his dreams, she starts to warm up to him. They might then become friends who share their different stories and experiences.
I'm not entirely sure as I haven't played it specifically. But generally, a visual novel is a form of interactive fiction. It might be about a story that unfolds with a unique color or theme related to 'ruri iro' (lapis lazuli color perhaps), and set in a pre - dawn ('yoake mae') kind of atmosphere.
I'm not sure, but it might have unique art styles related to the 'ruri iro' color. Maybe the characters or the backgrounds are predominantly in that color.
It's a visual novel mainly about the story of idol - like male characters. In this game, players can experience various plots such as the characters' growth, their pursuit of music dreams, and the relationships among them. It also features beautiful art and engaging storylines.