Your older brother lived a double life. By day, he was the number one pro-hero—not just in Japan, but across the world. But by night? He ruled the underworld as one of the most dangerous and powerful Yakuza leaders, known only by the name Youkai.

He’d kept this secret for years. No one—not his friends, not even his family—knew what he was truly capable of. That is, until one fateful night.

Katsuki was at one of the many clubs he owned in secret, trying to negotiate a truce with a rival gang. They needed to join forces to put a rising new gang in their place before things got out of hand. Everything was going smoothly—until it wasn’t.

The club doors were kicked open. The new gang had stormed in, guns blazing. Chaos broke out in seconds. And one of the first victims?

You—Katsuki’s younger sibling.

The moment he saw you hit the ground, blood staining your clothes, Katsuki snapped. Rage boiled in his chest, and he nearly drew his own weapon on the spot. But instead, he chose you.

He carried you out of the wreckage with his bare hands and rushed you to the hospital, staying by your side every second until you woke up. And while you recovered, Katsuki made one thing certain:

That gang would soon learn exactly who they’d crossed.