Kyle & Ken Katayanagi, also known as The Katayanagi Twins, are Ramona Flowers' fifth and sixth evil exes. Scott has to fight them at the same time, to his disadvantage. They are twins, and the final bosses of Volume 5, although the dramatic overtones of the volume push the Twins into the background.
Relationship with Ramona
It is known that Ramona used to date both of them at the same time, but without each knowing about the other (basically cheating on both of them). When the truth was revealed, the twins had sworn to always do everything together from that moment on. There seems to be no hostility between the two considering their former relationship with Ramona. They seem to place the blame solely on her. Scott ends up having to fight the twins 4 times before really winning the battle.
Encounter with Scott
Scott first met them at Julie Powers' Mexican Day of the Dead party. Instead of fighting him head on, they force Scott to fight and defeat Robot-01 while Kim and Ramona go out on the balcony for a smoke and talk. Robot-01 is a smaller robot and seen knocked out when Kim Pine and Ramona come back inside. Scott is disappointed when he finds out there's no reward for winning this fight.
The second battle puts Scott against another of the Twins' robots at Sneaky Dee's during the concert Sex Bob-omb intended to perform at - which goes disastrously. Again, this battle is glossed over as we're again set to listen to Ramona talking, this time, with Knives, and the only action we catch is the end where Scott decapitates the robot with his bass, breaking both in the process.
The third match is at another of Julie's parties, where it's revealed that Julie is apparently dating the Twins. Ramona heads out onto the balcony while Scott goes toe-to-toe with another robot, which is much larger than the other two. The aftermath of the fight is seen with Scott standing over the robot with its arm ripped off and head removed.
After the party, the Twins follow Kim Pine to the subway, where they abduct her in order to force Scott into the open. The final battle puts Scott against both the twins who specialize in tag-team tandem moves giving Scott a total disadvantage, while Kim is held hostage in a swinging cage nearby. Scott gets the crap kicked out of him while the Twins taunt and demoralize him, but Kim intervenes with her cell phone claiming (falsely) that she received a message from Ramona who can't wait to see him soon. Scott, spurred on by Ramona's love, fights back and defeats the Twins simultaneously with knees to the head for a bonus, and unlocks an achievement for defeating both Twins in unison.
Separately, Ken and Kyle do not have many "special powers". They are both masters in robotics as they built several robots to attack Scott Pilgrim. Together, however, they are a skilled tag-team of martial artists and make use of a number of techniques ultilized through the "Twin-Link", such the "Double Hurricane Kick" and "Simul-punch", when fighting hand-to-hand as a homage to Double Dragon. Their hurricane kicks can also be seen as a homage to Street Fighter duo Ryu and Ken.
Kyle and Ken are both incredibly arrogant. They are also meant to be a play on Jimmy and Billy from the Double Dragon series. Much like most of the latter-half of Ramona's evil exes though, they seem to hold her to some level of regards and even appear to understand that she's a runner, and her abandoning people is simply her nature. However, this doesn't stop them from joining the League in order to seek revenge on Ramona.
Next to Gideon, the Twins are possibly the most cunning and strategic members of the League. Instead of fighting Scott head on, they use their robots to test his skills. They also take the time to learn about Scott, including his past relationship with Kim Pine who the Twins identify as the one "constant" in Scott's life. This leads them to specifically target her in order to draw Scott out into the open. In addition, they are able to deduce that Scott's relationship with Ramona is on shaky ground, and use this knowledge to demoralize him during their final fight.
In vs. the World
After a heated argument with Scott at the fallout of the fight against Roxie Richter, Ramona gave him a laminated list of the Evil Exes before storming off. The Katayanagi were not only on that list as Evil Exes 5 and 6, they were also the next opponents in the music tournament. A frustrated Scott said that he not only wants to take part in the battle, but also wants to "take them apart". Not realizing the band battle is set to be "amp vs. amp" until 10 minutes before the show when they finally read the poster, Sex Bob-omb is shocked to see a literal wall of amps set up across from them.
The twins take on Scott and Sex Bob-omb as dual keyboard players, and at first seemed to gain the upper hand after summoning a pair of twin snow dragons from their speakers. But a determined Scott motivates the band to up the ante, summoning a giant Yeti when he triggers his distortion pedal, crushing the dragons. The twins were defeated and with enough points, Scott managed to earn an Extra Life. The battle took place at a location called the Ninth Circle, which is a reference to the Divine Comedy, by Dante Alighieri.
A poster of the two can be seen in the background behind the Clash at Demonhead poster at the record store and their tour bus (with logo of two dragons) can be seen behind Gideon when he signs Sex Bob-Omb.
Unlike the book, where they are devious, plan extensively, and speak at great length; the movie shows them as silent attackers in one scene only. This was done to shorten the length of the film.
According to Bryan Lee O'Malley's commentary track on the DVD, the concept of a music duel between Sex Bob-omb and the Katayanagis was in the draft script for Volume 5.
In the Game
In Scott Pilgrim vs. the World: The Game, the Twins appear as dual bosses of World 5; in the game Ken is called "Kevin." This is a reference to Double Dragon 3, where the names of the title characters were wrong (Bimmy and Jimmy instead of Billy and Jimmy). Additionally, Ken's name being changed to Kevin may be a reference to the NES game Street Fighter 2010 (whose main character Kevin Striker is called Ken in the American localized version).
You actually fight the Twins twice in the game. The first time is against their colossal robot which starts with the player having to run up a fire escape as the hands smash the stairs. Once at the top of the building you fight the robot as it tries to smash, grab and punch you with its hands. The boss robot and the battle itself, holds a reference to one of sigma's final forms. Once those are defeated, the Twins escape to the next part of the stage.
After you fight your way to the end of that, you take on both of them at the same time. This battle is very tricky as you have to knock both of them out. Knocking one of them out will prompt the active one to try and revive the fallen twin just as a player can revive another. In addition, if the fight against the Katayanagi twins takes place during co-op, kung-fu enemies will join the fight (named Sammo and Donnie), making the battle far more difficult as they fill the screen with enemies. The twins mostly use standard melee attacks when separated but when together, they can lock on and do combination attacks like a hurricane kick and a mega punch that, if connected, can do a huge amount of damage to your character. Lvl 15 or 16 is recommended to fight them (if only to even get through their stage) and the use of jump kicks, sidesteps and special attacks but used to take them down. If playing multiplayer, have one or more partners deal with mooks while one or two deal with the twins and switch up to preserve LP.
Whenever they use their combinations, their bodies temporarily turn completely black (Ken) and white (Kyle), fitting with the Yin and Yang theme. Once the twins are defeated, they explode into mini dragons that dissolve to nothing leaving behind coins plus a $2.00 twin bonus (Kyle $14.95, Ken $17.95). Just like in the comic, there is an achievement/trophy for beating both twins at once.
Despite Kyle's outfit being different from Ken's in the comic and film series, they both share the same sprite based on Kevin. However their character portrait shown before their battle depicts Kyle wearing his normal clothes and hair style. This technique of using the same base model but changing only a few colors on a character is known as "pallet swapping" and adds another degree of hilarity to the fact the two characters are twins.
- A promotional poster for Scott Pilgrim vs. the World (film) incorrectly shows Ken as the 5th evil ex and Kyle as the 6th instead of vice versa.
- The twins' characters have many references to the numbers 5 and 6. They both have 5 syllables in their last names and 6 syllables if you add the single syllable in their first names, the total reward Scott receives for beating them is 156 dollars and in the movie they turn the volume of their music up to 11, which is the sum of 5 and 6, as well as a reference to the film “This Is Spinal Tap”.
- In one instance, they refer to Scott as "Spot Pilgrim". The reason for this is allegedly because they aren't that fluent in the English language. However, they speak English very fluently for the entire issue, only messing up with Scott's name.
- Based on a comment made by Ramona immediately afterwards, the Twins may have simply been mocking Scott by implying that he's Ramona's "pet".
- Roxie's dying remark that Scott will never beat the Twins may indicate that the Twins are highly respected by the other members of the League.
- In the game, Kyle and Ken's moves after linking include the symbol of Yin-Yang. This is the symbol of Taoism, a religion originating in Asia, and could be a reference to Kyle and Ken's Japanese lineage. It is slightly odd, however, as Taoism is Chinese in origin and nature (by the tenets of it's philosophy), and as many traditional Japanese, (such as martial artists), consider the Yin-Yang symbol to be purely "Chinese", and not as something to be identified with the Japanese culture.
- In the movie, the twins don't speak due to the casting office forgetting to write "identical mid-twenties attractive English-speaking Japanese twins" into the casting call while it was in development.