Overall, the Shippo and Kirara lemon fanfiction can be a creative exploration of their characters, but it also has the potential to deviate quite a bit from the source material. It's important to note that such fanfictions should be read with an open mind and understanding of the different interpretations that fans can have.
Yes, there might be. You can try searching on fanfic platforms like Archive of Our Own or FanFiction.net. Sometimes these types of crossovers are created by fans who are interested in both gj bu kirara and kyoya.
One common theme is the exploration of their unspoken bond. Since they are both part of the Inuyasha group, they might have a connection that wasn't fully explored in the original. Another theme could be the transformation of their relationship over time. In lemon fanfiction, this could lead to a romantic or more physical relationship.
Since there's not much information given, it's hard to say exactly. It might be a crossover fanfic if Kirara and Kyoro are from different sources. 'gj bu' could be an abbreviation related to the overall theme, like a group name or a special place in the fan - created universe. Maybe it's a story exploring their relationship, whether it's friendship, rivalry or something else.
Another way is through character backstories. If the fanfiction delves into their pasts, perhaps they find out that they have some sort of connection from long ago. This connection can be explored and can bring them closer together. For instance, they might discover that their families were once allies, and this realization makes them see each other in a new light.