Hisaya Miki

is a freshman at St. Ishiyama High School, and a member of the Six Horsemen- or the Rokkisei. He was once a friend of Oga and Furuichi, who went to their middle school. He was friends with Oga, as he looked up to his strength and wished to be strong as well. After sometime he had to move to Nara, saddened as despite not growing any stronger, he had a great time.

History
One day after the three were coming home from an abandoned factory, Miki went back to the factory to get back a charm he forgot. When he got there, a gang that had made the factory their hang out beat him up. Oga thinking something was wrong went back and looked for Miki, finding him beaten up by a gang, when Oga was fighting, Miki attempted to fight the gang leader, who easily beat him and, using two of his nails, which were rather long and sharp, scratched Miki in the face creating his trademark scar. But even then, Miki was grateful for Oga defending him, making him feel that he was truely Oga's friend. On the day before he moved, the gang came to their school looking for Oga. Miki quickly went to help Oga, only for Oga to beat him up and call him pathetic. This caused Miki to hate Oga, and he later moved back, and when he entered St. Ishiyama he begged Kaname Izuma to teach him martial arts, looking to defeat Oga.

Saint Ishiyama High Arc
When Oga entered St. Ishiyama High School, Miki was overjoyed to finally fight Oga. He quickly started a quarrel that ended in a tie. Later after a volley ball match between Ishiyama High and the Rokkisei, the Gang's leader that had beat up Miki, went looking for Oga for revenge. Miki was eager to fight him as well, but the gang leader later remember him from the fight, in which the gang leader revealed that he was going to move to Nara as well. Miki then realized that Oga had beat him up, so the gang leader would not have a motive, and leave him alone. As such Miki felt great remorse, that he had hated Oga. Afterwards, he would attempt to befriend Oga once more.

Abilities
Having been thoroughly trained in martial arts, he relies on his agility to evade Oga's attacks, and is the one person so far who has come out of a fight with him unscathed. However, most of his own attacks, although strong enough to take down Kanzaki, fail to have much of an effect on stronger thugs like Oga and Toujou. The Izuma style finisher (the Black Owl Killer) is strong enough to take down Oga in one hit, but it must be stressed that Oga actually intended to take the blow to measure Mikki's strength, and made no effort to dodge it. His own resilience does not seem particularly high, as he was quite affected by two hits from Teimou's shadow forces, and was saved from further injury by Oga. He is also inexperienced when it comes to fighting multiple opponents at once, as shown when he had trouble fighting members from Teimou's Shadow Forces.