Can someone tell me what this even means?
Explaining what something is, using the word in the explanation is unhelpful lol. Anyway, I can't name a single game I own where the MC is only a bottom. When it comes to gay stuff anyway. Games generally give you the choice on what you want to do, so by default the character is whatever you are. (Non-Linear stories at least).
If you don't mind text based stuff (With a little bit of visuals), Lillith's Throne has an option after winning combat, to still submit. And you can make it so all the characters who spawn are men.
You're good, I got the gist of what you meant for the nojin thing, except for the word itself lol. Oo, another good one is Tales of Androgyny. There is stuff where MC tops, but the maain focus of the game is being in a submissive position. 90% of the CG's are the main character getting topped in someway. Really beautiful game too. Both the writing and the art.
Potentially Lust Odyssey as well? I haven't played it in a while. But I do remember very few characters (Like 2) being mainly submissive characters which you can avoid or just be friendly with. Everyone else is naturally dominant towards you. I think the most dominant thing you're railroaded into is as a power bottom. But a bottom nonetheless. (Unlike ToA this one is completely m/m focused) The tops in the game are peak. (I don't like the CG's that much, but the character sprites are great)