Character catalog
A character catalog is a library of AI bots you browse and switch between. It is a different job from one ongoing girlfriend.
A character catalog is a library of AI characters. You pick one, talk for a while, and move on to another when you feel like it. Character AI is the large example, and many pages listing “alternatives” are really lists of other catalogs.
That suits browsing and trying things out. It is a different thing from an AI girlfriend, where you stay with one person and the history between you keeps growing.
Riho has no catalog. There is one girlfriend, and she is yours from the first conversation. If you are leaving a library, see Character AI alternatives, or read Riho vs Character AI for the two side by side.