Tanaka Yukio is the main character in Beck. In the beginning of the anime he is an unassured youngster who lets everyone to boss him around. Yukio is unfamiliar with the modern rock bands. Including the popular band The Dying Breed. In the beginning his girlfriend Izumi starts to talk to him about rock music, takes him to concerts of the local rock band and gives him his first album of Dying Breed. One day Yukio ( or Koyuki like his friends call him) comes home from school and notices a few guys who are torturing a weird looking dog. He manages to save it and after that meets the dogs owner. The genius guitarist Minami Ryūsuke. A few days later he runs into Ryūsuke again and sees how much everyone loves him. Koyuki gets his first guitar from Ryūsuke and with some help from the weird Saitou-san he starts learning how to play it. Yukio stays unassured of himself for a while, until he meets Ryūsuke's sister - Minami Maho. Strange feelings start to appear in both Maho and Koyuki which Ryūsuke encourages. Koyuki is the last one to join the band Beck. He takes the role of a second guitarist and second vocals. Everyone in the band is amassed by his talent and voice, and thus he becomes one of the most important members of the band. Koyuki is confident in the success of the band Beck and he doesn't give up 'till the end.