Perennial Dusk -Kinsenka- | Frontwing

The protagonist of the story: A ruthless boy who cannot feel pain in his heart. His younger sister, his only family, is the one person he treasures, and anyone who torments her is met with a brutal end by his hands... Yet, yearning to understand the human heart, he often interrogates his victims, even though they cannot respond.

Just as he begins to seek respite from his bleak life, his unexpected encounter with Benio Matsuri causes him to experience a kind of pain akin to love in his heart.