Bowsareach

Bowsareach is the poly ship between Mario, Princess Peach and Bowser from the Super Mario fandom.

Canon
Mario, Princess Peach, and Bowser have known each other since childhood, as evidenced by Mario and Luigi: Partners in Time and ''Yoshi's Island. However, it would appear Mario and Bowser had known each other the longest due to him having Kamek kidnap Mario and Luigi in Yoshi's Island'', with Mario managing to escape. Eventually, Princess Peach and Mario became friends as children. Bowser would later begin to grow attached to Peach, but the feeling wasn't mutual.

As the years went on, Bowser would begin kidnapping Princess Peach due to both a megalomaniac desire to rule the world, but also because he had fallen in love with her. Due to Mario and Peach's friendship, Mario is always the one to stop Bowser. With every instance, Mario ends up defeating Bowser and saving Peach. Bowser has come close to stopping Mario, as shown in Paper Mario and Super Mario Odyssey, but Mario always wins in some shape or form. For almost every rescue, Peach would reward Mario with a kiss, cake, or both.

However, in Super Princess Peach, the roles are reversed in which Peach rescues Mario from Bowser. During the final boss of the game, Bowser is shown to be impressed by her managing to defeat his minions. Once Bowser is swung out of his own castle, Peach practically rushes towards Mario, even going so far as to push his brother, Luigi, away. The game ends with Mario, Peach, Luigi, Perry the Parasol, and a few Toads returning to the Mushroom Kingdom.

Although Mario and Peach are shown to either be angry or frightened by the koopa, they also have a history of working together with him when necessary. Games such as Super Paper Mario have all three members be playable characters working together, Super Mario RPG also has Peach and Bowser as party members. Mario also allows Bowser to join sports events and parties. In Bowser's Inside Story, Bowser is even given a cake made by Peach.

Fanon
Similar to the premise of its sister ship, Bowsario, the ship mainly revolves around Bowser stopping his constant kidnappings. However, unlike Bowsario, all three decide to enter a poly relationship. The concept of the ship had existed since the three character become more developed as the years went on, but popularity increased more after the release of Super Mario Odyssey. Due to the themes of weddings, some fans felt it would be fitting if the rivalry ended with all three together.