Okuyasu as seen in The Book: JoJo's Bizarre Adventure 4th Another Day
Okuyasu with his stand The Hand
Okuyasu, fatally wounded by Killer Queen
Okuyasu Nijimura (虹村 億泰, Nijimura Okuyasu) is a central character and core ally in Part IV: Diamond is Unbreakable.
Introduced as an antagonist, Okuyasu soon becomes Josuke Higashikata's best friend. They stay close friends throughout Part 4, and presumably onwards after.
Okuyasu is a young man of above-average height and medium to athletic build.
Two fine lines cross his face, in semicircles passing the inner corners of his eyes. He wears a small pompadour, resting high on his crown; the hair at his sides light and combed back closely.
He wears a dark, modified Japanese school uniform. He wears a double-breasted jacket, which he decorates with metallic/golden emblems including a yen (¥) sign on the right of his collar and a dollar ($) sign on his left (more accurately, a cifrão; with two vertical lines); along with a larger dollar sign in the middle of his chest. On his right shoulder he has printed "億" ("Oku", the kanji for 100,000,000); variously replaced with the word "TRILLION" in large, light letters between his shoulder and elbow; mirroring the word "BILLION" on his left.
He wears two slim, sagging belts at the top of wide-legged pants.
Okuyasu describes himself as stupid. However; he is consistently friendly, loyal and cheerful. He tended to rely on his elder brother Keicho Nijimura to make difficult decisions.
After Akira Otoishi and Yoshikage Kira murder his brother Keicho and friend Shigekiyo, respectively, Okuyasu shows a desire for vengeance.
Okuyasu has been known to say that he is "not good at making decisions". He punches out Akira Otoishi through luck when presented with the choice between him masquerading as a Speedwagon Foundation employee and a real one.
Okuyasu is affected by Koichi's relationship with Yukako Yamagishi; mildly (comically) envious of his success.
Okuyasu's Stand, The Hand, "cuts" out space; replaced with redistributed neighbouring space; or eradicated. It can also be limited to physical substance removal as seen in a few occasions, functioning identical to Cream's void in this case.
Okuyasu's father has mutated into a bizarre creature due to Dio's spores when Okuyasu was only 7. Searching with his brother Keicho Nijimura for a way to kill their father and put him out of his misery, the Nijimura brothers start using the Bow and Arrow in possession of Keicho to find a user capable of killing him.
In their search for a stand capable of killing their father, the Nijimura brothers end up shooting Koichi Hirose, giving him Echoes. This attracts Josuke Higashikata's attention and a fight ensues. Okuyasu, due to not being very bright, ends up causing his own defeat and even enters in the attack range of Bad Company. After explaining his story, Keicho is killed by the Stand Red Hot Chili Pepper, who steals the Bow and Arrow.
Okuyasu sought revenge against its user, but almost died in the battle. He eventually managed to protect Joseph Joestar from the user Akira Otoishi, being responsible for his arrest.
During this time and the following events surrounding Yoshikage Kira, he became fast friends with Josuke, Shigekiyo Yangu and Koichi.
Okuyasu recieves the benefit of Tonio Trussardi's cooking and his Stand Pearl Jam; deeply affected physically and emotionally.
He rather dislikes Rohan Kishibe because of what Rohan tried to do to him in their fight, making Okuyasu burn himself while transformed in a living book for trying to save Koichi.
Okuyasu's value of friendship is the reason he became enraged when Shigechi was killed by Yoshikage Kira. In their search for Kira the group encountered his father Yoshihiro Kira, but Okuyasu couldn't help them because he was outside of Atom Heart Father's depicted area.
Okuyasu also fought Toyohiro Kanedaichi, but was unable to hit him as a result of Super Fly reflecting his attacks.
Eventually Okuyasu seemingly dies after suffering mortal wounds during a battle with Yoshikage Kira, only to return after meeting his brother in a dream. Keicho asks him where he wants to go and Okuyasu answers that he wants "to go back to Morioh" which results in him waking up.
He appears at the end to say goodbye to Reimi Sugimoto, claiming that he will be lonely without her (just like Rohan).
(The information below derives from a Light Novel not written by Araki. As such, it may or may not be considered canon.)
Okuyasu helps in the investigation of Hanae Orikasa's death. He eventually comes across the killer Takuma Hasumi and chases him to the library, where they engage in battle. Okuyasu's experience and instincts turn out to be useful against the inexperienced stand user, causing serious injuries to him, but ends up being defeated. Nonetheless, Okuyasu contributes to Josuke's victory by telling him how the killer fights.
Okuyasu makes a brief appearance, hearing Rohan's story about Nanase Kishibe along with Koichi and Josuke. Okuyasu tells Rohan he always reminded him of Mona Lisa and asked for him to imitate her pose for a photo. Rohan left to investigate Nizaemon Yamamura's painting without saying anything, making Okuyasu say he didn't mean to insult Rohan.
Okuyasu appears at the end of the story, again enjoying Tonio Trussardi's cuisine.
Okuyasu makes his game debut in the PS3 title, as a playable character, he was confirmed for the game along with Josuke, Jolyne and Ermes.
Since Okuyasu didn't fight many enemies during the events of PART IV, his moveset is mostly based on his Stand ability and his own strong kicks and punches since he's a "hot head" type of character. Okuyasu only has two special moves (one having two variations), but he can add more pressure on it's attack, the higher the pressure, the more powerful and distant the attack becomes. Using his Stand's ability, he can erase any space by creating strong vaccums, Okuyasu can both "teleport" ahead of his position or bring the opponent near him, he can also make The Hand use it's ability in order to make a lower attack in form of a spin (similiar to how he fought against Akira).
His HHA makes Okuyasu use The Hand in order to erase the immediate area in front of him, it can delayed to increase the damage and range. His GHA has him use his Stand to repeatedly attack the opponent with his power, then after a final hit, he grins before a random flowerpot flies out of nowhere and hits him right in the face, causing damage to himself as well (similiar to how his fight against Josuke proceded), causing a small percent of damage on himself (making Okuyasu the only character who can damage himself with an GHA special move in the game).
Okuyasu posses one alternate costume, based on a moment during the event with Pearl Jam, where he took his school jacket off revealing a tank top underneath it. Aside from being a playable character, Okuyasu also appears in the stage "Kira Estate" as a background character along with Koichi. Obviously if Okuyasu is one of the two fighting characters in that stage, he will not appear in the stage's background.
Okuyasu as seen in The Book: JoJo's Bizarre Adventure 4th Another Day
Okuyasu with his stand The Hand
Okuyasu, fatally wounded by Killer Queen
Okuyasu as a figure
Okuyasu as he appears in All-Star Battle
Okuyasu Costume A in All Star Battle
All Star Battle concept art