once the Dragon Balls were collected. Toriyama said that although the stories are purposefully easy to understand, he specifically aimed Dragon Ball at an older audience than Dr. Slump. The manga was not popular initially. Although he suspected the fighting genre would appeal more to its shōnen audience, Toriyama tried to stick to the Journey to the West adventure aspect which he himself enjoyed. Such as having the setting change each chapter, different enemies popping up, and different locations. It was only after he became tired of Torishima nagging about its popularity that Toriyama gave in and developed more battles with the first shown Tenkaichi Budōkai. Despite his reluctance, the author said it felt good when the series picked up in popularity at that point. However, he said he still tried to resist by returning to the adventure aspect with the Red Ribbon Army arc, and visiting Penguin Village from Dr. Slump to add comedy. When that did not work out, fighting became the main theme for the manga. Toriyama said that by the second half of the series, he had become more interested in coming up with the story than drawing it, and that the battles became more intense by him simplifying the lines. He also said he would get letters from readers complaining that the art had become "too square", so he intentionally made it more so. Years later he stated that because Dragon Ball is an action manga the most important aspect is the sense of speed, so he did not draw very elaborately, suggesting that he was not interested in the art. As the manga progressed, Toriyama struggled with the Android and Cell arc, feeling that he could not outdo the Freeza arc. He added time travel, but said he had a hard time with the plot, only being able to think of what to do that week. After Cell's death, Toriyama intended for Gohan to replace Goku as the series' protagonist, but felt the character was not suited for it and changed his mind. Even after the Cell arc, Toriyama felt it could not end there and so continued to the Majin Boo arc. Having resolved it would be the finale, he decided to draw what he wanted and inserted comedy with Gohan's Great Saiyaman persona and the character Gotenks. However, he did not think of an ending until the final chapter. At the time,