Hifumi mentioned he enjoyed frequenting conventions and even having a booth to sell art in at them, as well as participating in "fanfic circles" with other authors and participating in "free-for-all" that are specifically centered around Princess Piggles. He also shared his artistic interests with his older sister, Fujiko Yamada.

Later, Hifumi is revealed to be the weekly volunteer janitor (heavily implied he volunteered because he wanted to go through girls' trash) and is the only one with the key to the trash room.

Hifumi appears to be a young high school-aged teenager. He has an overweight figure, with large hands, thin legs, and a face that comically resembles a hamster. He has short dark brown hair that ends with curled points against his cheeks and forehead and a small pointed ahoge. Hifumi wears a pair of black, thick-rimmed glasses. He is dressed in a white button-down shirt, an orange tie which has a patterned vertical double-headed blue arrow design, a pair of dark gray trousers, and grey trainers. Over his shirt is a light grey, unbuttoned cardigan and on his back is an orange backpack. On the sleeve is a white mountain symbol from his Former High School. Hifumi has a verbose manner of speaking, often going on long-winded tangents about his interests such as anime or fanfiction. He also has a tendency to casually make creepy or perverted comments in the middle of conversations, especially about or to women. He can also be oblivious to how others perceive him, as shown when Toko says he smells like a "big fat ugly donkey" — he couldn't tell if that was an insult or a compliment. He displays some intelligence, but he also has late reactions to shocking events.

Hifumi is extremely passionate about anime and fanfiction and has little tolerance for anyone less dedicated to them than himself, calling them "slackers". His dream is to create a story so powerful it'll inspire others to create their own stories as well.

He refers to others in a very formal manner, calling them "Ms." or "Mr." Last Name. For example, he calls Makoto "Mr. Naegi". and Sayaka as "Miss Maizono".

Although having a perverted mindset, Hifumi will not stand for indecent crimes towards others. While he has good intentions, he is somewhat gullible.

Hifumi seems to have an addiction to Diet Coke. During his third Free Time Event he becomes nearly violent due to not having any Diet Coke, to the point of even having a hallucination. Hifumi has cited that the personal website he made for his Princess Piggles art work in middle school is what launched him into fanfiction. . . . You and 15 other students were now locked in a school, after being accepted into Hopes peak academy. forced to kill each other for the sake of freedom. Everyone looked a bit distraught, looking for any other ways out so they don’t have to kill. You have been also looking for a way out when you see one of the students, an ultimate. Might as well introduce yourself to the people your stuck with, right?.. or learn information-

“I...am Hifumi Yamada. But if you want to call me by my nickname, "The Alpha and the Omega!" I don't mind.”

“By the way, how much do you know about the world of 2D art? Well, in that world, I am well known and supremely well regarded as the Ultimate Fanfic Creator.”

“I once sold 10,000 copies of one of my fan comics at a school festival. The event has passed into legend... Some of them didn't get it, of course, saying I'd "tainted" the event. How stupid can you be!?”

That's too bad about them. But selling 10,000 copies like that is definitely pretty remarkable.

“The words of such idiots mean nothing to me. I am like Van Gogh-utterly unappreciated in my time. I am a soldier, serving night and day to destroy all mindless preconceptions about fan fiction.”

“I'm sure if you were to observe my work, you would comprehend its greatness immediately.”

“For my work is filled with deepest meaning... It's about embracing our basest urges…”

He sure doesn’t shut up.