It's hard to say it's a widely 'popular' genre in the traditional sense. While there may be some fans who explore such themes in fanfiction, it's not something that represents the mainstream of Splatoon fan works. The Splatoon series is mainly known for its unique gameplay and colorful characters, and most fanfiction focuses on things like character relationships, adventures in the Splatoon world, and interpretations of the game's lore. However, in the vast realm of fan-created content, there will always be a small subset of more niche or out - of - the - ordinary concepts like this.
I'm not entirely sure. It's possible that there are new characters introduced in Sword Art Online vol 15. The series often expands its cast as the story progresses, so new characters could be added to bring new plotlines or challenges.
In the Sword Art Online vol 9 light novel on Goodreads, we can expect a lot. Since the series is set in a virtual reality gaming world, this volume might explore deeper into the mechanics of the game. There could be a focus on the lore of the game world, how it was created and what secrets it holds. The relationships between the characters, especially romantic ones like Kirito and Asuna, might take new turns. And of course, there will be intense battles and strategic planning as they try to overcome the various obstacles in the game.
The Splatoon manga is indeed canon. It contributes to the broader narrative and world-building of Splatoon. Any variations from other elements are usually intentional and part of the creative process to expand the story.
The story length of Splatoon 3 can vary depending on how quickly you progress and how much you explore. Generally, it can take several hours to complete the main story missions.