Tenma and his party head to the royal castle, where they reunite with old friends and encounter familiar faces from the past, including Aina, Aura's mysterious older sister. Why is Aura so deathly afraid of her?

Tenma finally registers for the martial arts tournament with a familiar (but new!) follower and is thrilled to see even more old friends again, including a certain beautiful knight captain and a mischievous trio of catgirls. The tournament starts off with a bang, but soon tragedy strikes when a formidable competitor seriously injures one of Tenma's dearest friends. Who is this mystery enemy, and will Tenma's cheat abilities be enough to beat them?