A quiet and shy individual, Daisuke Wakui wasn't a major fixture of class 3-3. He was present on Kouichi Sakakbibara's first day of school, but did not welcome his new classmate, though he did move out of the way so others could. In "Build Limbs", when Izumi began enforcing her new countermeasures, which involved ignoring Kouichi, he tried to ask Daisuke what was going on, but Daisuke was unable to tell his neighbor. He was present when Kubodera killed himself in the middle of class, but wasn't part of the group who fled right away, he was seen vomiting on the floor before he pulled himself together and walked out.
In "Glass Eye", Daisuke was one of the students who went on the class trip. During the first night's dinner, he had an asthma attack. The cartridge for his inhaler was depleted. Before this an envelope containing an inhaler/cartridge was shown on top of the table, at the corner between Daisuke and Tomohiko. Chibiki-sensei asked if there was a spare cartridge, and Daisuke weakly shook his head. Telephone service at the lodge was out and not-yet-repaired. Cellphones could get a tower, but service wouldn't go through. So Chibiki-sensei drove him down the mountain to a hospital.
He has short brown hair and nearly closed eyes, and his skin is noticeably pale. He wears the school standard male uniform.
Daisuke seems a little sick, so he is usually alone and takes a rest quietly in his seat.
- Daisuke sits in class in the second column of desks from the hallway, third from the front. He sits behind Noboru Saruta. Aya Ayano sits to his left, Aki Matsui to his right and Kouichi Sakakibara behind him.
- Daisuke's voice actor's name was learned in the end credits of "Sphere Joint", though as yet he'd had no spoken dialogue. His first line was "ugh," the sounds of puking, a reasonable response after his teacher had just killed himself in front of the class.
- Also in "Sphere Joint" his eyes are briefly seen as black.
- He is ranked C in Another characters ranking.
- His first name, Daisuke, means "great help."
- His home address is 2-12 Furuikecho Yomiyama City.
- In Chapter 16 of the manga, it was not Daisuke who suddenly fell sick during dinner, as he never appears in the manga. . When Izumi and Mei were arguing, Izumi blamed Mei and Kouichi for all that had happened. When Kouichi tried to protect Mei, he suddenly collapsed.
- The event is used from Episode 10.
- At 178 cm, Daisuke is the tallest character in the series.
- Daisuke doesn't appear in the live action film. However, a composite character of himself and Takako does exist, Sakurako Wakui. Sakurako is Izumi's best friend and her roommate on the class trip, has an overall appearance based on Takako from the manga, and has the same last name as Daisuke. Unlike every other version of Takako, however, she manages to survive the calamity.