Usually, when I introduce Cosmic Fish in comicbookhour or webcomicchat, I tend to say it's a comic about monsters, identities, and healing and it's true but there's a lot I'm obviously avoiding for now while the story is still stretching out with its ideas. The concept of the "monsters/ghosts" already detaches from the typical story by removing the concept of monster hunter and only hinting from the perspective of one of these creatures who tends to avoid conflict after a series of horrible experiences in the past the comic is currently showing (some). So at first it's a lot of "hearsay" of what she's been told or what she's technically and indirectly telling the reader to believe based on her certainty and her questions, and not because it's just convenient at the time. (I hate stories that purposely avoid characters from asking the obvious questions, it just turns them into plot tools)
As the story progresses, you start to see cracks in the character's statements (all of them) as they all find themselves in a gray area: the reality of one of the ghosts is that humans are awful, the other one sees no problem as they were raised by one, another simply doesn't care but shifts the blame of their situation on the guardians that protect the planet, eventually you start to see the guardians' perspectives (as they choose to take care of the ones who are "SUPPOSED to exist" and not ghosts), so on and so forth. And as the characters start having each other's realities clash, they begin to grow and form new opinions throughout the story as well as grow themselves by starting to question their thoughts/actions, and in extension, how they can affect others. (This begins to cover their own identity (be it mental, gender/sexual, etc, and how to heal from a dark mental state of doubt, anxiety, and depression).
And the mental state of the ghost is by far the most important bit of the characters. How they find themselves in their state of mind reflects how they start to physically change and in turns extends the question is "THAT who I really am/meant to be?" Which is really why the term of "ghost" is used more often rather than just "monster". It's how they view themselves as something that SHOULDN'T exist, and if it reaches a point of monstrous (again based on perspective of what that means) , something that CAN'T exist nor it can be "saved". (the latter is important too)
So I can only cover the explanation of how I introduce the comic to the readers, but there's SO MUCH I wish I could cover, but if I'm confident enough to share the tidbits of how ghosts work, at least know that it's just the tip of the iceberg. It's a complicated story, I guess? And the focus at the end of the day is characters trying to uncover what it really means to be happy and in the end, who they are and can be in a grander scale. The story IS the characters rather than the world they live in which is full of story and its own history but you rarely get to experience THIS bit first hand (since it doesn't affect the characters) but rather the worlds they choose to create. So it's highly a story about perspective......metaphoricallyandliterally.
By literally I mean...space is involved. And then science kicks in. And then things get crazy. And it's so fun but this is entering spoiler territory, but it begins to clear up why the plot itself is shown in different points in a timeline rather than a chronological order.
I'm so sorry this is long D|
Tl;Dr: It's a story about a person's view of oneself/how others see them based on their own perception of reality, and how they can choose to react to the world around them with the knowledge obtained. Also, space is awesome but it can cause existential dread.