The length of Kokomi's story quest can vary depending on your playstyle and how quickly you progress through the tasks. Generally, it might take a few hours to complete.
A good Kokomi x Saiki fanfic often has well - developed characters. It should stay true to the original personalities of Kokomi and Saiki while also exploring new aspects of them in the context of their relationship. For example, if Kokomi is usually calm and collected in the original work, the fanfic should maintain that essence while showing how she might act differently around Saiki.
You can try looking on fanfiction websites like Archive of Our Own (AO3) or FanFiction.net. These platforms often have a wide variety of fanfics, including ones about Kokomi and Saiki. Just use the search function and type in 'Kokomi x Saiki' to see what pops up.
One popular story could be 'The Unusual Bond' which explores the unique relationship between Saiki Kusuo and Kokomi in a rather interesting way. It might not be as common as other types of fanfictions, but it has its own charm.
As of now, the Genshin manga is not finished. The story is still evolving and there's more to come for fans to enjoy. The creators are taking their time to develop a rich and engaging narrative.
There's no definite answer yet. It might continue if there's enough demand and the creative team has more story to tell. But it could also stop if they feel they've completed the story arc.