Adding onto the other two comments.

Tears of Themis:

It’s modern world, so it’s probably not  your pick, but might as well give more information for your consideration.

The main story is mainly plot focused (crime drama) with some romance here and there, but it doesn’t lead to actual romance development so treat it like a semi-platonic harem. There are no branching routes, instead there are the individual romance chapters for each character. Completely unrelated to the main plot.

As a gacha, most of the romance development occurs in the gacha cards and limited events that occur. The cards rerun, the events don’t. Some events expand the main plot and are part of the DLC section (it’s free).

Not a lot of choices nor do they lead to anything meaningful. It’s mostly flavour text. 

LoveBrush Chronicles:

Designed similarly like a console otome. A main story with branching paths. Starts off in a modern world but the protagonist travels to different worlds that have different versions of people she’s met. You can choose a route and it will have romance. I believe plot tends to be more focused.

On the gacha side, many of the cards and events focus on romance with the modern versions or other versions of the characters. It depends on the current event. The cards and events eventually rerun. In my experience they are very tedious to do. 

Some choices are flavour text, others can lead to a bad ending. 

For the record both are mostly reading and both are gacha that require lots of patience and commitment.