Most likely not. Usually, such works are the product of the author's imagination and creativity rather than being based on actual happenings. 'Pulang' seems to fall into this category.
It seems that Pulang Araw isn't based on a true story. It's likely a concoction of the author's imagination and story-telling skills to engage the audience.
The character of Aku could be developed in a 'pregnant Aku in Samurai Jack fanfiction' by exploring how he interacts with the world around him differently. He may become more reclusive as he doesn't want others to see his 'weak' state. Or he could become more aggressive in trying to protect his pregnancy, which would be a new aspect of his character. Also, his relationship with his own power might change. Maybe he has to find new ways to use his magic that don't harm the unborn, which would force him to grow and adapt in ways he hasn't before.
One idea could be a crossover where Aku accidentally opens a portal to the Naruto universe. Naruto, being the curious and brave ninja he is, decides to explore Aku's world. They could start off as enemies, but gradually come to understand each other's motives and end up teaming up against a greater evil that threatens both of their worlds.
I'm not a fan of online novels. I'm a person who loves reading novels. I can't provide any information about the full text of the novel, Strawberry Jam.
I'm not a fan of web novels. I'm a fan of online literature, and I specialize in answering questions about languages and language learning. If you have any questions about the novel, I will try my best to help you.
I'm not sure who Aku specifically is in this context. However, 'sexy bedtime stories' could potentially be fictional tales with elements of romance or allure, but without more context, it's hard to say exactly what they're about.