The Worst Pair

Sworn Enemies is the fourth chapter of the Owari no Seraph manga.

Summary
The chapter begins with a new day as Yu makes his way to class. In the hallway, he has a run-in with a lanky, squinty-eyed young man with glasses and short hair. They basically bump into each other and fight.

Later on, his face covered in bruises from his scuffle, Yu meets up with Yoichi and Shinoa to head to their first class for learning the fine art of killing vampires. While Yu would still prefer to just hit the battlefield in full sprint, he still has to attend these rather ironic classes in order to be properly equipped and outfitted for the job. In class, they find that Guren Ichinose is their homeroom teacher, and the two boys are introduced as the idiot and the crybaby. Yu makes less of a self introduction to the class, and more of a proclamation that these 'classes' are little more than a lame formality for him to have to cull through before he can get equipment like the kind Guren has at his side. Yu then gets seated in front of the same lanky delinquent as before, which of course results in another fight.

Guren bashes them both unconscious, and the bespectacled (and bruised) delinquent Shiho Kimizuki later visits Guren in his office to inquire about the same subject of interest as Yu - when he would be tested to be outfitted with Cursed Gear, specifically of the Black Demon Series. Time is of a greater concern to Kimizuki though, because his little sister has contracted the same virus that wiped out all but ten percent of the human population 8 years prior, even though children below the age of thirteen are not supposed to be affected by it. If Kimizuki advances into the Army's elite forces, he'll have access to better care and treatment methods for his sister. Despite Kimizuki being at the top of his class in all subjects though, Guren remains unconvinced that the boy would not hold his own against a demon weapon once he's touched it. Demons latch onto desires and feed off the worst emotions humans can feel, and Guren felt the boy's desire to save his sister may wind up being turned against him if he tried. Guren unsheaths his sword, just to give the boy a taste of the demonic malevolence the demon weapons had in store for him.

The next day, the two stooges are being assessed for their abilities in combat. Yu tries to team up with Yoichi, but Shinoa promptly throws herself at the timid one just so Yu would have no choice but to partner up with Kimizuki. The teacher then handcuffs all partners together with suspicious accuracy, and animated a myriad of mannequins which the partners must destroy in order to receive class credit. At the very beginning of the test though, Kimizuki hears word that his sister had gone through a relapse. At first trying to power his way through the test first, Yu convinces him that the test wasn't nearly as important as being there for his little sister. The two leave and visit the little girl in the hospital wing, still handcuffed together. While Kimizuki mused over having lost the points he needed to advance, it appears his kindness swayed Shinoa enough to recommend that Kimizuki and Yu be tested for the Black Demon weapons right away. Guren smiles, and decides to start making preparations to oust the Main Family from their throne by force.

Chapter Notes
Kimizuki is just as strong or stronger than Yu in a fight.

Guren is setting the stage for a massive coup to take over the military.