In 1999, Shuu is a tall, skinny teenager with light skin, short grey hair with sideswept bangs, and black eyes. He wears a white short-sleeved button-up shirt, black trousers held up with a black belt with a dark grey buckle, and a pair of round glasses.
In 2002, Shuu is now a young man, taller than average and with slightly more chiseled facial features. His hair is somewhat messier, though still short, and he now wears oval glasses. He wears a white turtleneck sweater, a dark brown jacket, grey pants and tan shoes.
On December 31, Shuu is shown wearing a maroon turtleneck sweater under a big puffy orange jacket, as well as dark blue pants.
In 2027, Shuu wears a light blue coat with a mandarin collar and grey pants.
On March 1995, Shuu was over at a friend's house, so he wasn't at home to witness the battle between Greymon and Parrotmon. Four years later, though he was at a club training camp away from Tokyo the time of Myotismon's attack, he saw the Digital World in the night sky.
In 2000, Shuu was studying medicine. However, after attending one of Haruhiko Takenouchi's anthropology lectures, he decided to change his major and start paying his own tuition. He confided in his younger brother, Joe, before telling his parents.
In 2002, Shuu is helping Professor Takenouchi with his research in Kyoto when an Apemon attacks him. Luckily, Ken Ichijouji and Stingmon arrive to deliver Poromon to Yolei Inoue, who is in Kyoto on a class trip. Stingmon is able to subdue the Apemon and take him back to the Digital World. Hearing Yolei speak of Digimon, Shuu and Professor Takenouchi introduce themselves and give her a ride. Shuu is thrilled to see a Digimon, having missed his chances several times before. Shuu sees Shurimon's battle against a Musyamon, and holds Professor Takenouchi's laptop for Yolei to open a Digi Port and send it back to the Digital World. When the Digimon disappear and Yolei wonders why they came to the Real World, the Professor theorizes they may have had a reason even if said it doesn't make sense to them. When Shuu leaves Yolei at her class's meeting point, he asks her to say hi to Joe.
On December, when Yukio Oikawa and his minions kidnap Ken, Shuu arrives to give the younger DigiDestined a ride. After dropping Yolei, Kari and their Digimon on the way, he and the boys get into a car chase with the truck Ken is in, but are set back by a train barrier and a road block. When MarineDevimon attempts to attack a hospital, Shuu, T.K. and Cody go inside to help evacuate patients. He later drives them to Highton View Terrace so they could reunite with the others and fight Daemon. After the battle, he drives the DigiDestined back home and apologizes to their parents for keeping them out late. Inadvertently, while he is apologizing to Davis's mother, he catches the interest of Davis's sister, Jun, who develops a crush on him.
He continues to help the DigiDestined during their stakeout on the Dark Spore infected children, along with Professor Takenouchi and his wife.On December 31, he is present at the summer camp with the DigiDestined's families, alongside his older brother, Shin. This is the only time Shin and Shuu are seen together.
At some point, he became a DigiDestined.
In 2027, Shuu is the member of a research team with Haruhiko Takenouchi and Izzy Izumi, studying more of the Digital World than what the human population already knows.