Hot Springing a Leak! (Japanese: ウリムートリオと湯けむりバトル！！ The Urimoo Trio and the Hot Spring Battle!!) is the 63rd episode of Pokémon the Series: Diamond and Pearl, and the 529th episode of the Pokémon anime. It first aired in Japan on January 17, 2008 and in the United States on June 28, 2008.
When it's late and there's no Pokémon Center nearby, Dawn comes up with the solution: a visit to a nearby hot spring hotel, owned by the parents of her old friend Leona! Dawn and her friends arrive at the hotel ready for a relaxing soak in the springs, only to find Leona and her three Swinub in crisis mode because the spring water has stopped flowing. Now Leona is counting on her Swinub to use their superb sense of smell and sniff out another hot spring source.
With Dawn and her friends along to help, Leona follows the Swinub to the site of a new hot spring hotel. The construction workers are Team Rocket in disguise, and they claim to have found this spring water on their own. Leona notices the spring water here is just like the water back home, leading her to suspect they've been tapping into her hotel's pipeline. Right on cue, a Wooper shows up with the proof she needs to prove this "new" spring really is just the diverted water from her family's hot spring!
Team Rocket throws aside their disguises and unleashes a new robot, the Badabing Super Soaker Number Six. The robot is no match for Dawn and Leona's teamwork, and once Team Rocket is dealt with, the hot spring can start to flow again. But first, Dawn and Leona, using Piplup and Swinub, have a Tag Battle against Brock and Ash, who use Sudowoodo and Chimchar. After a frosty draw, everyone heads to the hot springs for a great soak to psych themselves up for the adventures ahead!
As Ash and his friends continue to travel, Ash is still hard at work training his Turtwig in using Energy Ball. Turtwig charges the sphere and proceeds to launch it, but the sphere dissipates beforehand. Turtwig is upset, but Ash encourages it to try again. Brock asks for him to hold off until they reach the next town, in order to get there before dark. Ash recalls Turtwig and looks forward to a hot bath at the next Pokémon Center, but Brock checks his guidebook and finds no Center in the next town. Dawn suggests that they go to a hot spring that she knows about, one that allows Pokémon to enjoy it as well. She mentions that one of her best friends lives at a hot spring hotel, so they start heading that way.
Outside the hotel, a girl talks to her Swinub in helping her out. Dawn calls out her name, Leona, Dawn's childhood friend. Leona happens to call her Dee-Dee, which upsets Dawn, but Leona is still happy to see her. When asked about how business is going, Leona admits that it has been sluggish. Leona remembers watching Dawn's most recentContest performance, which slightly upsets Dawn. Dawn introduces Leona to Ash and Brock, mentioning that she met Dawn in Kindergarten. Hearing that Leona is a Trainer as well, Ash asks her for a battle, but Leona doesn't have the time. Dawn is eager to jump in the hot spring, but before Leona can say anything, they're off.
They find the hot spring, with Ash jumping in first, but they find the pool shallow and cold. Leona mentions that the spring is not running because a week ago, the spring suddenly stopped receiving water. Since the spring is fed from a pipeline leading down from the mountain, Leona's parents decided to hike up and inspect it. Leona admits that if the situation doesn't change soon, the hotel will have to close. Leona is planning to use her Swinub to find another hot spring, which Dawn checks with her Pokédex. The Swinub even know how to use Dig. The thought of Leona raising her Pokémon makes Dawn reflect on her kindergarten days when Leona comforted her about when a young boy proceeded to bully others and hog a Jungle Gym to himself, standing at the top like a ruler. It gives Dawn the plan for them to work together to find the hot spring. Leona's Swinub take the lead as they pike up a scent of a hot spring.
At a newer hot spring, a disguisedTeam Rocket takes pride in their work, wanting to open their business, as well as plans to let Giovanni have it. Leona's Swinub lead Ash and his friends to a source of steam. When they get there, they notice that a new hotel is being built with a freshly dug hot spring. Team Rocket notices them nearby as Meowth put sunglasses on and proceeds to push them off the property. Leona confronts them about the hotel. Meowth tells a story about them digging out the hot spring by hand. Leona can tell that the water is exactly the same as their hot spring water, just by sense. She believes that they have been diverting her hot spring water to use as their own. Jessie asks her for proof of possession about the water, which Leona knows will be difficult. Brock theorizes that if they tapped into the same water source that Leona's family does, but with a different pipe, it would not matter. It appears that Team rocket has won, when suddenly a Wooper appears from the pipe, with a transponder on its tail.
Ash checks the Wooper as Leona recognizes it as one that belongs to her parents. Leona's parents show up as they mention that when they checked their pipeline, the found another pipe attached directly to theirs, diverting water away from their hot spring. They sent the Wooper along the line to see where it led; revealing that the hot spring has been stolen. Team Rocket loses their disguises and recites their motto. Meowth pushes a switch and summons a mecha, firing water blasts at Ash and his friends. Pikachu wants to launch a Thunderbolt, but since everyone is soaking wet, Pikachu is forced to switch to Iron Tail, but Pikachu slips on the wet mecha, unable to make contact.
Dawn has another flashback about how she and Leona took down the bully before, so they decide to apply that tactic. Leona has her Swinub dig and cause the three-legged mecha to tumble and spill its water all over itself, heating it up. Dawn's Buneary then uses Ice Beam to quickly chill it, causing it to crack. The mecha tumbles backwards into Team Rocket and explodes, sending them blasting off. Dawn and Leona celebrate as Leona's parents insist that they stay for the spring, working to fix it.
Back at the hotel, Leona offers a Tag Battle, Ash and Brock against Dawn and Leona. Ash's Chimchar and Brock's Sudowoodo square off against Leona's Swinub and Dawn's Piplup. Swinub tries to Tackle Sudowoodo, but it dodges. Piplup tries to Peck Chimchar, but it Scratches Piplup down. Dawn and Leona team up as they switch targets, Swinub's Ice Shard against Chimchar with Piplup's Bubble Beam against Sudowoodo. Both dodge as Chimchar launches Flamethrower, both dodging. Chimchar tries Flame Wheel on Swinub, but Piplup takes the lead, triggering another flashback memory and tactic.
It appears that Chimchar hit, but neither target is to be seen. That's because Swinub dug underground, taking Piplup with it, springing up to hit Chimchar. Piplup hits with Whirlpool, soaking Chimchar. Ash and Brock feel the pressure as Dawn and Leona use the tactics that allowed them to take care of the bully. Piplup fires Bubble Beam at Chimchar, hitting, as Swinub launches Blizzard. Sudowoodo hits Swinub with Double-Edge, but the Blizzard hits Chimchar. Sudowoodo proceeds to Mimic the Blizzard as Swinub launches Blizzard, both sides getting hit. The end result shocks all as all four Pokémon have been frozen, resulting in a tie. They decide to end the day with the hot spring.
With the hot spring repaired, Ash and his friends as well as the Pokémon enjoy the hot spring. The Pokémon play and rest, Chimchar sitting with its tail above water while Sudowoodo sits near the steam without soaking its body. Buizel punches a flowing water stream. Leona praises them both as Ash decides to ask Leona about why Dawn is called Dee-Dee, but before she can respond, Dawn pushes her down, keeping the secret locked up. The next day, Ash and his friends leave the hot spring and wave Leona and her parents good bye, Dawn's confidence restored as well.
Dawn reuniting with Leona
Dawn reunites with her childhood friend Leona, while Ash and Brock meet her for the first time.
Dawn and Leona have a Tag Battle against Ash and Brock, which ends in a draw.