Rantaro and Sayaka have never met in canon, both are from different games in the Danganronpa series.
Rantaro is a carefree and relaxed person, he can get a bit overwhelmed by others. Sayaka is a bubbly, friendly, caring person. The two are different then each other. If the two were to be in a relationship, Sayaka's out-going, and bubbly personality could rub off on Rantaro. Maybe making him more comfortable around others.
Despite Sayaka idol career, Sayaka enjoys cooking, something in common with Rantaro. The two may not be similar, but some think the two can go together well. If the two were to be a thing, they could have very chill relationship.
Amaizono is a Crackhead ship and a rare pair ship in the Danganronpa fandom. The ship gets overlooked by over popular ships like, Oumami, which is a ship between Rantaro and Kokichi Oma, and Ikuzono, which is a ship between, Sayaka and Mukuro Ikusaba.
Art by SunChiiArts