No, Percy Jackson is an Epic Romance, the story of a boy who grows to sacrifice his humanity to protect the earth and loses it all, but the love oh his life, who manages to recover him from death with love and affection. The books are about Percy's and Annabeth's love.
First things first let's correct your gravest mistake
There is romance and romance.
"A romance is a narrative genre in literature that involves a mysterious, adventurous, or spiritual story line where the focus is on a quest that involves bravery and strong values, not always a love interest."
A Romance is a tale of a person, from beginning to end, and talks about their Quest or Journey. Most of the times, this is also the development of relationships over the course of their life. This could be Romantic Love, Fraternal Love, or any other kind, including even the love to things and dreams, like in the ROMANCE Don Quijote.
This is what a Romance is as a novel. Romance as in "from Rome", is a 12th century French term
A romantic story on the other hand, that has the GENRE romance , based on the 18th and 19th century definition of Romantic School of Poetry, And Romanticism, the artistic movement, from which books such as Romeo and Juliet sprouted, is a different thing.
You want this to be a Scholar Discussion, get your terms right first.