One common theme is friendship. Many fanfics explore how Mari and Anthony start as friends and how that relationship deepens. Another theme is self - discovery. As they interact, they often learn more about themselves.
One of the main themes in Omori's story is the exploration of the self. Omori is constantly trying to figure out who he is and what his place is in the world. Another important theme is the significance of relationships. His interactions with friends and foes alike shape his understanding of himself and his situation. Also, the theme of facing one's inner demons, which is closely related to mental health, is prevalent throughout the story.
I don't have the exact name of the person who created the Omori manga at hand. It could be worth doing a search on manga databases or asking fellow manga enthusiasts for the answer.
Omori is purely fictional. The story and characters were imagined by the creators, not drawn from real-life events. It offers a fantastical and imaginative experience for players.
At the moment, there's no definite date for the Omori manga release. But you can follow the official social media accounts or manga forums for any potential news or leaks.