Read these if you like Romance Between Humans And Magical Beings, When The Boy Helping The Protagonist Try To Confirm The Existence Of The River Monster Was The River Monster All Along, High School Glow-ups.
Listing 1 story.
A teenage girl befriends a solitary bookworm who summers in her lakeside town, hoping he can help her learn about a lake monster she believes she saw. Over the course of a few summers, the two fall in love. The girl eventually learns the boy is the lake monster, granted human form for three months of the year.