|Height||180 cm (5'11")|
|Affiliation||Higashi High Gang|
|Family||Father, Mother, Younger Brother|
|First Appearance||North South East West|
Summer Holidays Arc Edit
Okubo attends the summer festival with the rest of the Higashi delinquent gang. Stumbling around, he sees Minato crying while Maizono Yuto and Ryunosuke Himeji text each other. Maizono notices him, as does Minato, who instantly asks if he has a cell phone. Okubo replies that he dropped his while catching goldfish, and Minato weeps tears of joy.
Maizono and Himeji leave, and Minato asks if she can join Okubo for the rest of the night. He says yes, but warns her to stay at least 10 feet away for safety. Minato gives him a string cup phone, as neither of them have cellphones. He compliments her on her yukata, and Minato begins to furiously blush. They spend the rest of the time walking around, though Okubo has a hard time keeping up with Minato.
At 10 PM, Okubo offers to take Minato home. She asks if his bike still has a seat, and he replies that it does. However, when they go to check the bike, the seat has been replaced by a sunflower and note from the seat-thief.
A few days later, Okubo goes camping at Midori Ga Oka Academy with Maizono and Yamashita. However, because of Maizono's carefreeness and Okubo's unluckiness, they end up in the middle of a storm in a forest. Okubo notices a large building and they head inside for shelter.
Inside the building, the first room they go in is dimly lit. Okubo and Yamashita try to flee after seeing a ghost, but Maizono notices that the ghost, who is actually Hayasaka, is carrying candles in his hands. Okubo sighs in relief after Maizono confirms that Hayasaka is an ally.
Hayasaka tells the group that it would be fine for them to stay the night at the school. Okubo runs off to wash his hands, and goes to a bathroom stall. However, he finds that there is no more toilet paper. He asks for some, and nearby delinquents yelp in shock, believing that no one would be in the stalls so late at night. Under the belief that they would die if Okubo's request wasn't fulfilled, they quickly throw rolls of toilet paper at him.
Later, Okubo spots Maizono, but trips over in front of a staircase. Two students walk down the stairs, and stomp over his head while counting the number of steps.
As the rain pours down on Midori Ga Oka, the trio of Saitama delinquents go to sleep in the room beside Hayasakas'. They set up a tent, hammering tent stakes on the room's floor. Okubo and the others slither out of the tent like worms in their sleeping bags. The next day, they leave the school.