Ken Joshima is a confident and trusted member of Mukuro Rokudo's gang. He likes to tease and is an active person as well as being very eccentric. At certain times when he talks, he sometimes sticks his tongue out. He also has a large scar going from one cheek across the top of his nose and to the other cheek. Ken seems to utilize his Channels by inputing sets of animal teeth cartridges over his own which modify his physiology to reflect that of the animal he is using. When doing this, the face of the animal will appear on his cheek. He is always wearing a green Kokuyo Middle uniform. It is shown that he demonstrates great loyalty towards Mukuro Rokudo and will listen to all his orders. He often tries to show to others of his "obvious" dislike of Chrome, but it is seen that he actually cares for her, a secret that he doesn't wish others to know, though Chikusa already know of this since he accidently showed this out loud at the Sky Ring battle. In the anime, he often adds 'byon' after his sentences.
Ken is the first of Mukuro's gang seen targeting an unnamed character. Later, he tracks down Ryohei, who asks him to join his Boxing club. Ken accepts the proposition on the one condidition that Ryohei beats him in a fight. It is implied that Ken defeated Ryohei because the later he is seen in a hospital. It is at that time that Ken pulled 5 of Ryohei's teeth. (In the anime, he gave him a watch that read 5 o'clock.), showing him to be the fifth strongest Nami-Middle student.
Kokuyo Land Invasion
Ken throws dead dogs at Tsuna's group presumably to move them closer to the Botanical Dome. When Takeshi falls through the roof, he jumps in after him. He is amazed at how ditzy Yamamoto is in thinking that the dogs were actually puppets. Ken begins their battle by charging Takeshi, and when his opponent evades, he uses his momentum to leap into the air, put in the Monkey Channel, and then do a spinning wall-jump back towards Takeshi, who brings his bat out to defend. Ken uses the jaws of his Channel to destroy the bat with little fanfare. His opponent is visibly angered, but first asks him how he managed to change his appearance. Ken equates putting a new disc into a video game console to him putting teeth into his mouth to change his Channel. He demonstrates by switching the Monkey Channel for the Kong Channel, and heaving Takeshi into the glass walls of their arena. Off-screen, he switches to the Wolf Channel and reveals that because of the dead dogs' blood of Takeshi, he can smell him, while he can't be seen. And Ken proceeds to launch a flurry of quick attacks, which Takeshi dodges, trying to protect his arm. Reborn kicks Tsuna down into the arena, and Ken changes targets to the much weaker person. However, Takeshi throws a rock to get him to refocus on him. Ken charges and sinks the teeth of the Cheetah Channel deep into Takeshi's arm. However, he fell for the trap, and with a swift sword-butt to the temple, was knocked out by Takeshi. He taunts Tsuna's group after Takeshi and Tsuna are helped out of the hole, revealing that he managed to instantaneously switch to the Opossum Channel to effectively play dead. Bianchi proceeds to drop a large rock on his head. Ken reappears when Hayato is winning against Chikusa. He takes advantage of the fact that he has his back to him, and digs the claws of an unknown Channel deep into Hayato's chest, which was the debilitating blow that won them their fight. As he watches his and Chikusa's opponent stumble and fall down a flight of stairs, they dawdle and give him time to release Hibari. He is defeated off-screen and tossed out of the window.
Varia ArcKen and Chikusa appear escorting Chrome to the Mist Ring Battle. He unendingly states that he doesn't care for Chrome, and that they're only following her because Mukuro is housed in her body. But during the Sky Battle, Ken was constantly yelling that they couldn't see what was going on with Chrome. It's expected here that he cares for her. During the Sky Battle, it is revealed that Mukuro asked him and Chikusa to protect Tsuna with him. It can be assumed that they accepted.
Inheritance Succesion ArcThey appear when Kyoko, Haru, I-Pin, and Bianchi came to Kokuyo Land, asking where Chrome is. He replied saying that she's been missing since the day before yesterday (when Tsuna and the others came back from the Future). And said she ran off without saying anything, and he will give her the rice balls when she comes back.
Future ArcKen, along with Chikusa, makes a cameo appearance during Chrome's battle with Glo Xinia in a flashback. He was talking about their secret hiding hole and put gum in it, after which Chikusa commented that gum was not food. Ken, along with Mukuro and Chikusa, makes another appearance during Chrome's battle with Glo Xinia. All three of them appear as Real Illusions made from Chrome, with the help of her Vongola Mist Ring. He has recently appeared alongside Chikusa and M.M. after Fran freed Mukuro from Vendice. When they all arrived in Japan, they engaged Zakuro in combat but when he died, he began to watch the fight between Tsuna and Byakuran. After Tsuna defeated Byakuran, Ken was seen with Chikusa and Mukuro calling out Chrome that it's almost time they go back to the past.
- Channels: Ken utilizes his Channels by inputting sets of animal teeth cartridges over his own, which modify his physiology to reflect that of the animal. Those used by him, so far and in order of appearance:
- Monkey Channel - Agility, claws, fangs
- Kong Channel - Fangs, Strength
- Wolf Channel - Agility, claws, enhanced speed, fangs, a keen sense of smell
- Cheetah Channel - Fangs, greatly enhanced speed
- Opossum Channel - Ability to play dead
- Rhino Channel - Horns, strength
- Lion Channel - Claws, enhanced speed, fangs
Win-Loss Battle Record
- He does not fight with a Ring, but in a few Games, he's seen using Sun Flames.
- In the Reborn! Fandom, he is simply referred to as Ken. Like Lal, he is one of the only characters whose shorthand is already their name.
- Ken doesn't bathe daily and claims to only take a bath once a week or month.