There could be a fanfiction where Master Roshi discovers a new form of ki energy. He then tries to teach this to Goku and the others. In terms of the 'lemon' which is often associated with inappropriate content, we should shift our attention to the potential of the story in terms of exploring the Dragon Ball Z lore more deeply. For instance, how this new ki energy could change the power dynamics between the characters and lead to new battles and alliances.
One plot idea could be that Master Roshi discovers a new form of martial arts with the help of Lemon. Maybe Lemon has some unique abilities that she shares with Roshi, and together they develop a new style that combines her special skills with his vast experience. For example, if Lemon can communicate with animals in a special way, Roshi could use this to train in a more nature - oriented martial art.
It's a bit difficult as 'lemon' often implies adult - related content in fanfiction. But some fanfictions might focus on the comical side of Master Roshi. For example, there could be a story where he tries to compete in a cooking competition against the Saiyans, using his martial arts skills in cooking in a very funny way.
One interesting story could be Master Roshi imparting his unique wisdom, which is different from the normal Naruto teachings, to a young Naruto. Maybe he shows Naruto some unorthodox ways of chakra control.
There might be a dbz xenoverse lemon fanfiction where the story focuses on a romantic relationship between two characters from different timelines. This could involve them facing challenges not only in their relationship but also in the context of the Xenoverse's complex world. But again, due to the 'lemon' aspect, it may contain inappropriate content.
I'm not really into that kind of fanfiction, but you could try searching on some well - known fanfiction websites like FanFiction.net or Archive of Our Own. Maybe start by looking at the tags related to Roshi and Bulma.
They could also have a friendship - based relationship. They might share common interests like exploring new places or trying new types of food. They could have deep conversations about their dreams and fears, and support each other through difficult times.
There could be a fanfiction where Naruto and Roshi team up to face a common enemy. Maybe an enemy from Roshi's past that has somehow found its way into the Naruto universe. They would have to combine their different fighting styles, with Naruto's shadow clones and Rasengan, and Roshi's martial arts and energy blasts to defeat the foe.
Rather than looking for inappropriate content, we can explore the rich lore of Dragon Ball Z. For example, the concept of Super Saiyan transformations is really cool. Goku's first transformation into a Super Saiyan was a moment of high drama and it signified a major turning point in the series. We can also talk about the different forms of other characters like Trunks and Goten. There's so much to enjoy in the real DBZ universe without going into improper areas.
One interesting interaction could be when Android 18 challenges Master Roshi to a sparring match. Roshi, despite his age, shows some unexpected moves which surprises Android 18. This could lead to her respecting him more.
One popular dbz lemon fanfiction might be those that focus on the relationship between Goku and Chi - Chi, exploring their romantic side in a more in - depth way. However, it's important to note that fanfiction can vary greatly in quality and content.