This was greatly inspired by films such 1984's Splash, 2007's Fish Tales, and 2018's the Little Mermaid.
As a young boy Alastor is timid, shy, and has an extreme fear of water. While his mother loves and adores him, his father is ashamed of his son's skittish nature and emotionally and physically abused him to get him "To be brave."
One Summer when the family is vacationing at their beach house, they take a boat ride to sea and his father throws Alastor into the water to force him to learn to swim despite extreme protests from his wife. Alastor nearly drowns but is saved by a little girl who gives him a kiss which not only allows him to breathe underwater temporarily but forms a connection between them. However the two are separated when Alastor's mother pulls him out. Since no one else saw the girl, Alastor believes their encounter to be a near death hallucination.
Some time after this his mother becomes pregnant again and dies giving birth to a daughter. Alastor looks after his younger sister and protects her from their father's abuse until finally social services takes them out of his care. But rather than be separated from his sister through foster care, Alastor runs away with her and takes on the role of her guardian. But due to the abuse he becomes distant and refuses to form any relationship with anyone save for his younger sister.
Years pass, Alastor grows into a workaholic and anti-social young man with a job as a radio host who never dates or goes to any social events which concerns his pre-teen sister. When her school let's out for Summer break, she convinces Alastor to take a vacation or do something besides work every hour of everyday. He decides to take a Summer job at a radio station where their family's beach house is located.
They have to take a boat to get to the house but unfortunately Alastor accidentally falls off the boat and nearly drowns due to never having learned to swim because of his aquaphobia. However Alastor is rescued again, he doesn't understand how but his sister gets a glimpse of something underwater. Something with a fish tail and long blonde hair.
The next day a beautiful blonde woman named Charlotte "Charlie" comes to their house to return Alastor's wallet which he lost when he fell off the boat, claiming that she found it washed ashore on the beach. Both feel drawn to each other which confuses Alastor because he's never been attracted to any woman before. His sister notices this unspoken attraction and is suspicious of Charlie so she follows her to the beach one day and discovers that Charlie is in fact of mermaid. They befriend each other but Charlie swears the young girl to secrecy about what she is because she had recently escaped a circus which captured and imprisoned her. However Charlie cannot ever return home because years ago her father banished her for saving a human boy from drowning. Now she's all alone and has no where to go.
Alastor's sister correctly deduces that Charlie is the one who saved her brother when he was younger and gets the idea to set the two of them up together. Both Charlie and Alastor are against the idea but with help from their cleaning lady Niffty and one of their cranky neighbor's Husk, the two end up spending a lot time together. Despite Charlie's bubbly, outlandish behavior and Alastor's more aloof and distant personality, they bound over their shared passion for music and their difficult relationships with their fathers. Romance sparks between the radio host and the mermaid which eventually turns into a passionate love affair.
But trouble arises when Charlie's former captor Valentino comes to town with his circus and is desperate to recapture his biggest money maker. Even going as far as to brutally interrogate his other acts: Vaggie a fortune teller and Angel Dust an acrobat. Both loyal friends of Charlie who helped her escape and try to do everything they can to keep Valentino from finding her. Such as secretly visiting her at night by the cove to warn her about where Valentino is and how to best avoid him.
I thought this would be especially interesting because Charlie has a lot in common with media's most popular fictional mermaid characters. Like the original little mermaid character from the story but Hans Christian Anderson, she desires to reach heaven. Like Ariel in the Disney film she's gifted with a beautiful voice and has goals and a personality that differs from her family and species. And like Madison from Splash she's blonde, has a child-like innocence, a free spirit, and tries to see the good, beauty, and love in everything.