Professor Kukui announces to the class that they will be learning about Poké-Ping Pong, and he welcomes Ilima as a guest tutor. Ilima greets the class while his Eevee is on his shoulder before explaining the rules, but Ash remains uncertain of them. To demonstrate the rules, Ilima selects Lana as his opponent and sends out his Smeargle to go up against Lana's Popplio. Ilima serves the ball by hitting it with his racket, adding that Pokémon can use either a racket or attacks to hit the ball. Rotom records the demonstration game and states that the game functions as a set of three matches.
Ash and his classmates begin a series of practice sets across three Ping Pong tables. Though Ash grows tired of the games' repetitive nature. Kiawe challenges Ash to a real game, though the match is quickly quashed when Pikachu's Iron Tail causes the ball to hit Ash in the face twice. Meanwhile, Sophocles and Togedemaru begin to argue after missing the ball and colliding into each other mid-game against Lillie. Ilima arrives in the midst of chaos and settles the situation. He lectures Ash and Sophocles on the priority in Poke-Ping Pong, he states that empathy as key to a strong bond between Pokémon and partner. Sophocles goes on to apologize to Togedemaru and the others are encouraged by Ilima's words of wisdom. Professor Kukui brings out a score board, with Ash and Pikachu versus Mallow and Steenee as the first match up.
Steenee's scented Magical Leaf hits the ball across the net and as a secondary effect temporarily confuses Ash and Pikachu. The balls bounces off Pikachu's head and into Steenee's court. A Double Slap seals the fate of the game with Mallow taking the victory. Kiawe and Rotom are astounded how Mallow and Steenee's tactics changed quickly. Next game is Lillie against Sophocles, with Lillie taking the serving hit and the victory because Sophocles failed to hit the ball.
In the final match, Lana and Popplio face Kiawe and his Marowak. Kiawe throws his shirt and performs a Z-Move pose for an Inferno Overdrive serve. The dramatics prove to be faint, taking Lana by surprise, though she just manages to hit the ball. Marowak slams it with Shadow Bone and Popplio hits back with its fin, causing the ball to spin and change direction. The drive technique impresses Ilima, who tells Ash that Popplio hit the ball away and even changed its course. Kiawe manages to hit the ball before it hits the ground. Lana returns the ball and Marowak uses Iron Head to deflect it. Popplio's Aqua Jet hits but Kiawe catches the ball in time. Lana makes a Z-Move pose to use Hydro Vortex, though the feint proves almost successful. In a tantrum, Marowak throws its club and deflects the ball. Lana anticipated this, and actually has Popplio use Hydro Vortex, causing the ball to rush off and fall, soaking Kiawe and Marowak in the process. Kiawe and Marowak are frustrated because of the loss, but Lana clarifies that Kiawe got the point as the ball did not hit the board. The class had lots of fun, so Ilima invites them to see him play in the Pokémon Ping-Pong tournament next Sunday, to which they accept.
Sunday comes around and the group are sitting in the crowd anticipating the start of the tournament. Sophocles states there is a player who always wins every year. Kiawe refers to that player as Ikari the Dragon, and explains the nickname is because of the vibe he gives off. Mallow spots Ilima talking to Ikari on the courts in a heated exchange, though Ilima remains confident and calm. Ikari walks off with a gritted smile on his face. The first match begins, and Ikari calls on his Mienshao against a competitor and his Machamp. Despite having won a point Ikari scolds Mienshao for being soft. Kiawe and Mallow conclude Ikari's victory over Ilima last year and his lack of empathy is the reason why Ilima has returned for this year’s tournament.
Meanwhile, Ilima's match begins against Jessie, disguised in a blond wig and pink dress, with her Wobbuffet, who is wearing a brown wig. James and Meowth are in the sidelines cheering her on. Jessie serves and Ilima responding well. Wobbuffet uses Counter, and Smeargle uses its Sketch to copy the attack. In an attempt to earn Jessie the victory, Meowth shines off his charm, to blind Ilima. Though the strategy fails, Ilima hears the ball and hits it. Meowth then turns to Jessie and Wobbuffet, but accidentally shines the reflecting light onto them, causing them to miss the ball. Just as the score is called, Bewear drops through the ceiling, grabbing Team Rocket before jumping away with them, much to everyone's surprise.
Ilima and Ikari advance through to the final stage after competing in three rounds each, and are up against each other. The scene transition indicates there was sixteen competitors, including Jessie, Ilima, Ikari and his competitor with a Machamp. Eevee and fans offer Ilima sideline support. Mienshao's Pound gives Ikari One Love, putting him in an early lead. Ilima is unfazed, and he tells Smeargle that it is still early in the game. The next set evens the score, with the ball bouncing off Ikari's racket and hitting the ground. Several rounds pass, and the score is again even at 10 points each. Smeargle's drive hit causes Mienshao to miss, and gives Ilima an additional point.
Ikari becomes increasingly frustrated with Mienshao and Ilima and lecturing on his negative technique. Ikari serves the ball in an intense manner, though Ilima returns. Ikari has Mienshao use Drain Punch, and Smeargle returns the ball with a Sketch attack. Ikari slams the ball, however Ilima jumps and retaliates. Mienshao uses High Jump Kick, which Smeargle again uses Sketch to copy. The force causes Ikari's racket to shatter, and Mienshao jumps across Ikari to catch the ball, much to his shock. Ilima is declared victorious and thanks his Smeargle for its efforts. The two competitors shake hands, and Ilima apologizes for the out of turn lectures. Mienshao is seen nuzzling Ilima's Eevee and Smeargle. Ikari requests that Ilima not lose to anyone else before their next match up, Ilima agrees and thanks Ikari for being a good rival.
Ilima waves his goodbyes to his crying fans as he boards a ship destined for surrounding islands around Alola and onward to the Kalos region. Professor Kukui and his students are also on the dock watching Ilima's departure. Ilima promises to return one day, wishing everyone the very best in their goals. The ship leaves the dock, with the class waving to Ilima as he sails off into the distance.