The two was never ever seen interacting in canon besides being in Kaito's group for fighting against Monokuma. However, Rantaro has barely any interactions with anyone due to Rantaro being the first to die. Also, both characters are known for hiding their talent. In Rantaro's introduction, he refuses to tell Kaede his talent. But it was later revealed he was the Ultimate Survivor. Similarly, Maki lied to Kaede and told her that her talent was the Ultimate Child Caregiver, when it was really the Ultimate Assassain.
The two also have basically nothing in common due to them being the opposites, however, they do share a few vague similarities. Both are also responsible "older sibling" types, with Rantaro being the oldest of thirteen siblings. Meanwhile, Maki taking care of younger children at her old orphanage. As much similarities as they may share, there are also many differences. For example, Rantaro is usually a carefree and relaxed person. While Maki isn't and is very mean and unfriendly to the others.
Both of their personalities is based around them hiding most of their selves from others, but secretly caring a lot for the other students. Given the choice in the final trial, Maki offers to sacrifice herself to save the other survivors. However, in the end Maki chooses not to after being convinced out of it by Shuichi. The same choice is what led to Rantaro becoming the Ultimate Survivor, showing a similar willingness in the two to make difficult decisions for the good of others. Unfortunately, that decision by Rantaro is what caused the 53rd killing game.
The ship is a rare pair compared to other ships. Rival ships include Amamatsu and Harukaito. People may do so due to their dynamic. Maki and Rantaro are the more cool-minded, mysterious characters with hidden talents. Maki is also seen to get annoyed very easily, most of the time by characters that are too hyperactive like Kokichi Oma or overly cheerful like Angie Yonaga. Rantaro is neither so Rantaro could bring out Maki's smile like how Kaito Momota, her canon crush, does just by saying nice things to her. Their color schemes (green/blue + red/black) blend together as well.