Based on an imaginative love story of two characters of the anime (which Hajime Isayama owns) Attack on Titan, Annie Leonhardt and Eren Jaeger, "I stole a Tsundere's heart" is inspired to today's high school and romance.
forbidden romance trope
This follows the plot of AOT very loosely. Think of it more as an alternate timeline.
I of course do not own the rights to these characters. All rights to Attack on Titan go to Hajime Isayama.