"Akimoto-sensei, congratulations on the 30th anniversary of KochiKame! 30 years! For a lazy bum like me, such an incredible record is inconceivable. It is a total mystery where you hide such power within your skinny body and gentle smiling face. While our ages are not that far apart, you have been at this job a lot longer than I have, and it really means a lot to me to be able to do this collaboration manga with you. After all, I am appearing on the same pages as Ryo-san, who was famous before I became a manga artist. It is a huge honor, but I would rather not do this again (laughs)"
KochiKame (こち亀), full title Kochira Katsushika-ku Kameari Kōen Mae Hashutsujo (こちら葛飾区亀有公園前派出所; lit. "This is the Police Station in Front of Kameari Park in Katsushika Ward"), is a gag manga by Osamu Akimoto. It has appeared in several crossover video games with Dragon Ball, Kyutai Panic Adventure Returns!, as well as a special manga chapter co-written with Akira Toriyama.
KochiKame has been continuously serialized in Weekly Shōnen Jump since September 1976, and is the longest running manga series in history of the magazine so taking place in the present day, in and around a neighborhood police station (kōban) in the downtown part of Tokyo, KochiKame revolves around the misadventures of a middle-aged policeman named Ryotsu Kankichi (also called "Ryo-san").
Volume 69 (1991)
The Dragon Ball characters Frieza, Zarbon, and Appule appear in a two-page gag entirely made by Osamu Akimoto in KochiKame volume 69 (1991). Ryotsu Kankichi left on a journey, making it seem like the last chapter of KochiKame, but he immediately returns. Everyone is mad at him for tricking them like that. Ryo-san points out that he never explicitly said the series was ending, and says it is just a way of keeping things fresh. He then jokes about changing the series' name to KochiKame Z. His partner then decide to throw him into another manga, and he lands in Dragon Ball, during the Namek Saga.
30th anniversary (2006)
For the 30th anniversary of the serialization of KochiKame, in September 2006, Ryo-san makes a cameo in every manga serialized at the time in Weekly Shōnen Jump #46. Most notably, he has a full appearance as a marine in One Piece (chapter 428), and drinking alongside Don Patch in Bobobo-bo Bo-bobo. At the same time, a special manga called Chō KochiKame was released on September 15, 2006, and features the KochiKame characters in special crossover chapters with other Shōnen manga series: Golgo 13, Lupin III, Kinnikuman, and Dragon Ball.
The Dragon Ball crossover chapter is titled "Kochira Namekkusei Doragon Kōen Mae Hashutsujo" (こちらナメック星ドラゴン公園前派出所), and is based on the story in KochiKame volume 69. In this special nine-page chapter, Ryo-san is reassigned to planet Namek and has to deal with Frieza who parked his spaceship illegally. Vegeta, and Goku also make appearances. Frieza is waiting with Appule for the three other Namekian Dragon Balls to be found, when Ryotsu Kankichi comes and says that Frieza cannot park his spaceship there. Frieza uses a Death Beam to kill Ryotsu Kankichi but, to their surprise, he is still alive. Ryotsu Kankichi yells that they have to pay the fine and Frieza attacks him with an energy wave, which also fails to hurt Ryotsu Kankichi. When Ryotsu Kankichi pulls a Rocket Launcher out of the air, Appule says that there is no doubt and that Ryotsu Kankichi is a gag manga character. Frieza says he does not care because he is the strongest being in the universe and he fires blasts at Ryotsu Kankichi until he is tired. When even this does not kill Ryotsu Kankichi, Frieza leaves in his spaceship with Appule, and says that nothing happened. Ryotsu then meets Vegeta and, seeing that he wears the same type of Battle Armor as Frieza, he asks Vegeta if he knows the tyrant. Then, Goku's spaceship lands on the planet on the same place Frieza's ship was parked. Ryotsu tells Goku that he cannot park his ship there and the story ends.
Also, congratulatory pics from over 80 mangaka were published, many from Weekly Jump authors past and present, but also from other Shueisha mangaka and even from manga artists not associated with Shueisha such as Hiromu Arakawa (Fullmetal Alchemist) and Jyoji "George" Morikawa (Hajime no Ippo).
KochiKame is represented with Dragon Ball in the crossover games Famicom Jump: Hero Retsuden, Famicom Jump II: Saikyō no Shichinin, Cult Jump, Jump Super Stars, Jump Ultimate Stars, and J-Stars Victory Vs, with Ryotsu Kankichi being playable in the five last games.
Ryotsu Kankichi's encounter with Frieza in the manga crossover is referenced in some of these games such as J-Stars Victory Vs.