Sure. A lot of fanfiction authors explore the idea of Naruto being a master of water release. They might do this to show his growth beyond his original set of skills in the canon series. For example, he could use water release to counter fire - type jutsus more effectively, or he could develop a new signature water - based move that no one else in the Naruto universe has.
Maybe a plot where Naruto's Sound Release is related to an ancient and forgotten clan. He has to learn about his heritage to fully master this power. He could go on a journey to find the remnants of this clan and uncover secrets about his newfound ability along the way. This would involve a lot of exploration and interaction with different characters from the Naruto universe.
One possible plot could be that Naruto discovers a hidden water - release scroll. After studying it, he becomes proficient in water release. Then he uses this new skill to fight against a group of rogue ninjas who are strong against fire - type jutsus.
You can try looking on fanfiction websites like FanFiction.net or Archive of Our Own. Just search for 'Naruto Sound Release' in their search bars and you'll likely find some relevant fanfictions.
In fanfiction, Tobirama might use water - release to teach a young ninja. He could be passing on his knowledge of water - release to someone like a young Kakashi. He might show how to manipulate water in different forms, from a simple water bullet to a large - scale water dragon. This would not only be a great training arc but also a way to explore Tobirama's character more deeply.
A plotline could be Tobirama using water - release to create a hidden underwater base for Konoha. He uses his skills to carve out tunnels and chambers beneath the lake near the village. This base could be used for secret meetings or as a training ground for advanced water - release techniques.