MareShipping

MareShipping is the het ship between Ash and Bianca from the Pokémon fandom.

Canon
It all starts when a fake "Bianca" decided to play with Ash in flirts in Alto Mare secret garden, revealing her true identity as Latias. The real Bianca meets Ash and apologises to him, while her grandfather Lorenzo offers clarity of the situation. Bianca reveals that Latias has the unique ability to transform, and she often disguises herself as her, as they are best friends.

Lorenzo asks Ash to keep the secret garden and location of the Soul Dew a secret, and he agrees. With it getting late, Ash and Pikachu decide to leave the Secret Garden, much to Latias's dismay as she still wants to keep playing. Lorenzo takes Ash through a shortcut via his gondola workshop, while Bianca takes Ash the rest of the way by boat. Ash takes the opportunity to ask Bianca about the two girls who were chasing her before. Bianca is confused at first but realizes that it must have been Latias that was being pursued, which proves more concerning for her.

While Ash was with his friends in a bedroom, Lorenzo and Bianca rush over to the sacred pool, discovering the Soul Dew is now missing. Fearing something bad is about to unfold, they rush over to the museum to confront the culprits. Just ahead, Annie and Oakley reach the DMA inside the museum. Ariados tosses the exhausted Latios into a circular-marked area. A swirling cage then appears and carries Latios high into the air and begins to activate the DMA with his absorbed power. The protective gates around the mechanism disappear into the ground, with the control panel clearly in sight. Lorenzo and Bianca arrive but are quickly subdued by another of Espeon's Psychic attacks and Ariados's sticky web keeps them tied up. Oakley proceeds to place the Soul Dew into the designated holder, and the DMA swings into life.

Latias, meanwhile, has fled to the local Pokémon Center to ask for Ash's help, quickly transforming herself into Bianca. Pikachu alerts everyone to Latias's arrival, and Ash explains the peculiar situation to Brock and Misty. At Ash's request, Latias reveals her true form, stunning both Brock and Misty. The real Bianca ordered Latios to use sight sharing to bring Ash and Latias to the museum.

Latias soon receives a sight-sharing transmission from Latios at the museum, alerting Ash and friends to some of Annie and Oakley's evil schemes. Ash sees that Lorenzo and Bianca have been tied up, while the Soul Dew has been taken. Oakley greedily steps into the control pod by herself and ignores Lorenzo's protests as she resurrects the Aerodactyl and Kabutops that once threatened Alto Mare. Bianca and Lorenzo were soon freed and helped save Latios from being tortured by the DMA. Latios and Latias later stopped the tsunami wave from hitting Alto Mare. The following morning, Bianca and others searched for the guardians. While Latias was soon located, she learned of Latios's sacrificial death to save the town and received the new Soul Dew.

As Ash and his friends prepared to leave Alto Mare, Bianca was finishing a sketch of Ash and Pikachu. The drawing was later given to Ash by either Bianca, who had left her beret on her easel, or Latias in the form of Bianca: which remains the subject of ongoing debate. When Ash received the sketch, the girl kissed him. However, it's seen that Bianca's hat is left on the easel, pointing that Bianca possibly tried to look like Latias in her human guise by leaving her hat there so that Ash wouldn't think it was Bianca who kissed him. Bianca was seen again in the credits drawing another sketch by the harbor.

Fanon
This was formerly one of the most popular Pokémon anime ships, especially for nostalgic fans. It is often confused with AltoShipping (Ash x Latias), due to Latias taking the form of Bianca and some fans naming it with "Alto" for both Bianca and Latias in a pairing with Ash, though officially, the proper name for the couple of Ash and Bianca is MareShipping.

Previously, both ships were on par with each other among het ship fans and poképhilia ship fans. However, nowadays, most fans prefer MareShipping over AltoShipping due to the fact that fans see it rather strange to pair a human with a Pokémon. Because of this, Bianca is preferred over Latias as Ash's couple.

When Ash is handed the picture of him and Pikachu, it is thought by MareShippers to be Bianca, because Latias isn't known to be able to draw, and it's unusual for anyone to give away someone else's art. However, Pokémon themselves might not hold the same concepts of ownership, and is impossible to say if Latias would not give Ash something that wasn't hers, or if the sketch wasn't done for or by Latias, making it hers to give away, regardless. Whether the kiss was expected or not would be another question.

This ship at the time, rivaled many other ships, especially those that also involve girls kissing Ash on the cheeks or falling in love with him, such as KissShipping (Ash x Melody), FireShipping (Ash x Macey), AbilityShipping (Ash x Anabel), MorpheusShipping (Ash x Angie), PokéSilverShipping (Ash x Lyra), RedNaiveShipping (Ash x Jessie x James), apart from GoggleShipping (Ash x Giselle), where Ash has feelings for Giselle. However, almost all the girls involved in these ships were only occasional characters appearing only in that chapter or movie and none have ever appeared again, including Bianca, so they are currently overshadowed by all of ships of Ash x female companion protagonist of each season, even NegaiShipping.

Fandom
FAN FICTION
 * Ash/Bianca tag on FanFiction.net
 * Ash/Bianca tag on FanFiction.net

Trivia

 * The ship name, along with AltoShipping, comes from Alto Mare, the location in Johto as an anime-excluseve location, where Bianca lives and is protected by Latios and Latias.