Hyūga first appears to be very violent, a trait that seems to have been with him since middle school. He looks down on people weaker than him as weeds, and has no scruples about attacking people from behind. He describes himself as both serious and solitary, while Hansode Shiranui describes him as having a bad personality. After being "converted" by Medaka Kurokami however, Hyūga has mellowed out considerably, being much more willing to work with others. It is implied he has developed feelings for Medaka as well.
Hyūga has black eyes (usually squinted) and messy, dark purple hair (dark green in the anime). He wears the standard men's uniform of Hakoniwa Academy and a pair of glasses. He wears the kendo uniform when at the kendo hall. Ten years later, Hyūga wears a suit.
Student Council Executive Arc
Hyūga first appears asking Shiranui where Zenkichi Hitoyoshi is, only to be told that he has already been dragged off by Medaka. Shiranui then explains Zenkichi and Medaka's relationship to him. The next day, when Zenkichi and Shiranui are discussing the kendo hall, he remarks out loud that the delinquents better clear out. He later attacks Zenkichi from behind, knocking him out. He goes on to attack and defeat all the members of the Kendo Club, revealing that he didn't want to share the hall with anyone, and requested that Medaka clear out the hall so that he could have the then defunct Kendo Club all to himself. He is shocked when the members get back up, all of them declaring that they were once passionate about kendo as well, An enraged Hyūga attacks them, only to be stopped by Zenkichi. Hyūga demands to know why Zenkichi is protecting a bunch of thugs, to which Zenkichi replies that while he agrees with Hyūga, he agrees with Medaka more, and that he won't forgive anyone who tries to go against Medaka's justice. Hyūga angrily attacks him, only to be defeated with one punch to the face from Zenkichi. Hyūga gets away, promising to crush Zenkichi one day, but is caught by Medaka. She reveals that Shiranui has requested that she "Please fix Hyūga's bad personality." Medaka then promises Hyūga that she will see to it that he never wants to do evil again. What she actually does is not shown, though Hyūga's scream is heard across campus, and he later takes over the Kendo Club and shares the hall with the other members, though he sometimes butts heads with Mahibi Moji.
At a later date, while having lunch with Zenkichi and Shiranui, Hyūga discusses Zenkichi's recent status as the Student Council's "Club Typhoon", and that he should probably stop visiting all the clubs as he still hasn't joined one. Zenkichi replies that is fine, as he intended to make a name for himself anyway. Hearing this, Hisshuu Kanoya approaches him and asks to talk. When Hyūga asks Shiranui if it was alright to let Zenkichi leave with such a scary person, Shiranui replies that it is fine, and that she is only an acquaintance of Zenkichi. Hyūga comments that while he is quite scary himself, Shiranui is definitely the worst of all of them.
At the club battle swim meet, Hyūga is seen as one of the participants representing the Kendo Club, along with Moji. As usual, the two do not seem to be getting along. He and Moji take part in the second event, the three legged race. Both are seen shocked along with everyone else when Umumichi Yakushima and Sotsu Tanegashima begin swimming with their legs tied together, taking first place. At the end of the third event, the Kendo Club is in sixth place overall. During the final event, the cavalry battle, Hyūga is seen as one of Nekomi Nabeshima's victims when Tanzaku Aso explains how the Judo Club won the competition.
After Myouri Unzen blows up the Student Council office, Hyūga hears the commotion and questions Moji about it. When they both realize where the noise came from, they both brush it off as Medaka simply being up to her usual antics.
Kumagawa Incident Arc
Walking past the Student Council's office, Hyūga and Moji hear a horrified scream. Moji wonders at the noise, while Hyūga suggests that perhaps the Nonexistent Youth Bill has been confirmed. At the end of the semester, Hyūga is present for Medaka's speech. He is horrified by Misogi Kumagawa's new rules. On August twenty-second, Hyūga is among Medaka's former enemies who show up to cheer for her during the President's Battle.
Kurokami Medaka's Successor Arc
Unknown Shiranui Arc
The Kendo Club are approached by Medaka asking about Shiranui; none of them remember her. At the end of the academic year, Hyūga is among the students present at the Hakoniwa Academy graduation ceremony.
Bouquet Toss To The Future Arc
Hyūga is among the students who confront Medaka at the beginning of the 100 Flowers Run, holding flower number seventy-seven. He introduces himself and the students with him as the small fry characters army. He and the others are all blown away by Medaka's Kurokami Final. Hyūga thinks to himself that Medaka does not know how to hold back, but that is the reason everyone likes her. All present wonder if Medaka thinks of their time together as good memories. His message to Medaka is to live a magnificent life.
Ten years later, Hyūga is a banker.
Kendo Expert: Hyūga is a kendo expert recognized on a national level. He was able to defeat eight of his senior classman with no visible effort, though his strength ultimately couldn't compare to Zenkichi's.