After the battle against Zolgia, Basara returns to a peaceful life with his sisters, Mio and Maria. One day, as he prepares for the school sports festival, Basara is attacked by a person being manipulated by magic.
The day of the sports festival is finally here! Basara remains cautious of the enemy who manipulates people with magic, but still enjoys the sports festival with Mio and Yuki as the three of them compete in the four-legged-race.
After taking Kurumi hostage, Ornis robs Basara of the right arm wielding Bynhildr. Basara loses conciousness from the pain, but his sealed power is unleashed and goes on a rampage!
As the clash between the peaceful faction and the present demon lord draws near, Basara visits the peaceful faction with Mio. Basara enjoys the reunion until learning that a heavy punishment awaits Maria for her betrayal: a spanking while she is aroused?!
Ramsus seeks to extract the "Demon Lord's Power" from Mio without concern for her safety, which angers Basara. Just as sparks are about to fly, Shella leads Basara into the bath to try and help calm him down.
Basara and the others are called to Leohart's castle where Basara's father appears before them. He shares with them a message from Leohart: that they would hold a tournament before Leohart and Ramsus' forces to determine authority of the demon realm!
Basara and the others finally face the current demon lord, Leohart. Leohart's confidence in his strength fills the air as he welcomes them in without any tricks. Can breasts overcome brawn?
The group battle between Leohart and Ramsus's forces finally begins. After Mio wins the first match, Maria tries to face Lars in close combat. Will she have enough power to win the battle?
The final match of the tournament begins! Basara faces Leohart, and the two demon swords clash in fierce battle. Will Basara's secret strategy tilt the fight in his favor?
The council's rampage sends quakes through the demon realm! The demon Chaos is called forth, seeking to claim Basara, Mio, and Leohart's lives. Do they even stand a chance of victory with this supreme being before them?!
What's the best way to celebrate a birthday? Well, to the succubus Maria, there's only one thing to do-get Mio and Basara to hook up! Using the guise of Mio's birthday, and a lust spell, she's determined to have the perfect setup for a sexy celebration.