Yū Kondō debuted in Shueisha as an editor for shōjo manga. He was in charge of Akira Toriyama's work immediately after his transfer Shueisha's Weekly Shōnen Jump magazine. Kondō was involved with the Dragon Ball manga during its most popular times, taking over Kazuhiko Torishima's position following the end of the Piccolo Jr. Saga, and leaving shortly after the Perfect Cell Saga. Yū Kondō has a calm and reassuring personality, and he always listened to the female readers' advice and opinions, due to his experience in shōjo manga.
Under Yū Kondō, new plot elements meant to increase the manga's popularity were introduced in the series: aliens arrive on Earth (the Saiyans), the main character Goku is given a son (Gohan) and an older brother (Raditz), it is revealed that Goku himself is an alien, Goku teams up with his rival Piccolo, Goku dies, Great Apes return (with Vegeta and Gohan), the heroes travel to another planet (Namek), new transformations are introduced (notably, the popular Super Saiyan form), the time travel concept is introduced in the series, the Red Ribbon Army returns and the heroes battle powerful androids and other creatures (Cell). Yū Kondō had the idea to include more combat in the series, with battles more spectacular, against villains more and more powerful. It is during this period that the Power Level measurement was introduced in the series. Kondō is said to be Toriyama's inspiration for the villainous Frieza. Kondō, for his part, had always imagined himself as the basis for Future Trunks. When asked about this in Dragon Ball Forever, Toriyama denied consciously basing villainous characters on his editors, but admitted that he might have done so subconsciously.
Outside of Dragon Ball, Yū Kondō worked on Blue Exorcist and Sket Dance. Kondō is depicted in the 1994 manga Let's go in the Dog Eyebrows (犬マユゲでいこう, Inumayugedeikō) by Yuko Ishizuka, with his favorite phrase being "not good at all."