Ariados, Amigos (アリアドス！にんぽうバトル！！ Ariados! The Ninja Arts Battle!!) is the 19th episode of Pokémon: Johto League Champions.
While en route to Ecruteak City, Ash and co encounter a bush with legs. The legs in question belong to an Ariados. While trying to catch it they encounter Koga's sister Aya who is also trying to catch it. Little do they know that catching the Ariados, which belonged to her sensei, was part of her training. The sensei then invites Ash and his friends to train at the dojo. What will Ash and friends learn at this dojo?
Ash and Pikachu wash up and ask Brock where Misty went to. He recalls she went for a walk with Togepi. Misty puts a flower in her hair and asks Togepi how she looks. Togepi walks and trips over. Misty gets Togepi and sees something in the bush. She yells it is a bug, causing Ash, Brock and Pikachu to run to her. They study the bush a bit and Pikachu removes some parts and is intimidated by the size of the bug, while Misty yells "It is a big bug!" They see it is an Ariados, but has not moved a single bit. A woman appears, who searched Ariados for some time. They all recognize her as Aya, the ninja warrior from Fushia City. She recognizes the heroes, but removes Brock once Ariados wakes up after hearing to initiate a test. Venonat uses Stun Spore, but Ariados leaves by swinging using String Shot, so they all chase Ariados. Venonat cuts its string with Poison Sting and goes to Tackle it, but engulfs itself in a Spider Web. Brock realizes it was a trap made by Ariados to catch Venonat.
A voice that commanded Ariados to wakes up tells Aya not to let her guard down even for a little bit. The man appears before them and Aya introduces him as her tutor. Aya understands she has a lot to learn about Pokémon Trigitsu. The heroes are led to a dojo, where the trainers and Pokémon learn how to use moves in different aspects, by the tradition of Trigitsu. Aya comes with tea and Brock proposes she could be her tutor. Aya is surprised, so Brock sends Pineco, as he thinks they can be a better team under her guidance, though Pineco Self-Destructs. Aya proposes to her tutor to let them stay, so he agrees, pleasing Ash and Pikachu they can learn more about battling. Soon, Ash, Misty and Brock wear ninja outfits, and due to their outfit colors, Ash is sent to battling technique class, Brock to move boosting class and Misty to beauty and health class. Misty wants to go to battling classes, but is told that the beauty and health class is conducted once a year and trainers come from many regions to attend it. Hearing that, Misty decides to stay at the class.
However, Misty gets in a class with Spinarak. She tells it to be calm, although Spinarak, by its teacher's command, uses String Shot to envelop Misty's face, causing her to faint from the fear. Brock volunteers for his class, as his Pineco uses Spikes to pierce the balloons, showing speed and efficency. His teacher remarks his Pineco is well raised and Brock admits Pineco is an excellent teammate before Pineco happily Self-Destructs. At Ash's class, Hypno uses Hypnosis, but Houndour uses Smog, followed by a Feint Attack and defeats Hypno with Flamethrower. Next are Ash and Aya, using Bulbasaur and Venonat, each who have toughened up. Bulbasaur uses Vine Whip, outbalancing Venonat, followed by a Leech Seed. Venonat uses Supersonic, confusing Bulbasaur and goes to Tackle, but Bulbasaur jumps and wraps it with Vine Whip, then tosses it. Ash wins, but admits he was lucky to win, since Aya and Venonat are tough opponents. Team Rocket observes and think they should capture all Pokémon and sell it for many collectors.
At the night, Misty and Brock complain about what happened during their class but Ash is glad that he battled. Pikachu points at the window. Aya practices with Venonat, so Ash admits to her there aren't many trainers who train day and night. Suddenly, Venonat feels something and runs away. Soon, Aya and Ash hear trainers who report their Poké Balls have been stolen. They track the thieves (with Aya's tutor, Brock and Misty joining) and see Team Rocket are behind this, who want to show "a bit of magic". They come to their balloon with the stolen Poké Balls and capture their foe's Pikachu, then fly away. Aya's tutor jumps and unflods a kite, while Ariados uses String Shot to bind the kite to itself. Aya and the heroes follow the balloon. Tutor throws some throwing stars, causing Team Rocket's balloon to be pierced. Jessie sends Arbok, whose Poison Sting cuts Ariados' String Shot and rips the tutor's kite. The tutor throws more throwing stars, causing the net with the Poké Balls to fall down, as Brock catches it. Aya and Ash follow the balloon. Both the tutor and Team Rocket fall down, while Ash climbs a tree to save Pikachu.
Aya's tutor sees his Ariados is exhasuted, so tells Aya even if she did not learn everything, she needs to give her best, so Aya accepts the battle. Arbok goes to attack, but Venonat counters with Stun Spore. Arbok evades and uses Poison Sting against Venonat's. Venonat dodges, though Aya sees their opponent is strong. Her tutor reminds her of the training with Ariados, so Aya commands Venonat to Rest, so it goes asleep. Arbok Wraps it and while it seems Venonat will lose, it wakes up and paralyzes Arbok with Stun Spore. Venonat Tackles Arbok, tossing it to Team Rocket. They are confident they can attack together, even if their foe and his Pikachu come. However, Pikachu uses Thunderbolt, blasting them off into the night. Brock sees that Aya distracted Team Rocket, causing them to be overconfident when Venonat went asleep. Her tutor is impressed, as she leared the goal of Trigitsu is to turn weakness into strength. Next day, the heroes admit they learned a lot today. The tutor invites them to come back anytime, though Misty thinks she does not want that. Brock bids farewell to Aya and the heroes continue their journey to Ecruteak City. Team Rocket are hanging on a string made by Ariados and Wobbuffet comes out. The string is cut due to too much weight and they all fall down.
- This episode name is a pun on the Spanish statement "Adios, Amigos".
- The "Who's that Pokémon" is Jigglypuff.
- In the English dub, the flashback was entirely redubbed for unknown reasons.