Seitan Nakamura

is a main protagonist in the story Heart!. After learning about his father, Yoruko Nakamura, murdering his own father in a lab, he manipulates his father into doing whatever of Seitan's liking. Growing up as a sadistic teenager due to the mental trauma caused by his mother's murder, Seitan, joins the Bloody Mist Ninja Academy. After successfully graduating and murder the rest of his fellow graduating class, Seitan officially becomes a shinobi. His little brother, Saruto Nakamura, idolized him, training every day in his childhood to become a powerful ninja, not realizing the power both of them acquired.

After learning his father murdered his mother, Seitan and Saruto go head to head with their powerful father in Heart, learning of a powerful kekkei genkai hidden in Seitan, Thrust Release. After using it, the two boys were able to destroy their father, learning he has been dead for a long while but was being controlled by their grandfather, Ichiro Nakamura.