Oga VS Furuichi (男鹿VS古市 , Oga vs Furuichi) is chapter 173 of the Beelzebub manga.
Summary[]
Faced against one another, Oga and Furuichi commence their fight. They start off with a comical stance that subsequently leads to them reflecting on when they first fought against one another, which then leads to them trying to remember what is actually was. After trailing off, they finally start seriously fighting. However, after summoning both Xoblah and Vabam to help, both of whom being ultimately useless during the battle, Furuichi begins to hit a sinking point within defeat.
Knowing this, Oga asks that he stop fighting and explains that he will end up dying if he continues to his the Demonic tissues; to his surprise, he discovers that Furuichi already knew from Hecadoth much earlier. As he summons another Demon, he reveals to Oga that he is tired of the poor treatment that he receives from their peers and would rather die beating Oga then to live hollowly amongst the other students. With that said, Behemoth, who is the one that Furuichi ultimately summons, decides to help the young teenager.
Furuichi then begins to beat up Oga as his body slowly suffers from the amount of Demonic power within him. After a few additional attacks from both opponents, they end up taking their fight to the river waters, with Oga fighting under Super Milk Time and Furuichi with Behemoth's power. The two teenagers clash back-and-forth until the water surfs over them, concluding the fight.
In the end, Oga swims to the mainland while carrying a now-unconscious Furuichi. He sets Furuichi's body on the ground as he pants heavily, telling him that he remembers when they first fought seriously. Oga reminisces on the fight and tells his friend that he was the strongest that he fought until then; with that said, he collapses from exhaustion.