OMG SHAMELESS. Would you consider soul_campaign? I'm not sure what size/speed you were going for, but it meets your listed requirements. I'm afraid we can't offer you castmates, though. The basic premise is that there's a war against witches, and everyone brought into the city either turns into a literal weapon or wields one. It has an ongoing plot with frequent missions and events, but there's still room for slice of life.

It's a large game, but it's not too fast or difficult to play in, and our AC is very easy to meet. And I have yet to find anyone who isn't chill about backtags.

It's cutting a little close, our current app cycle ends February 15th at 11:59 PM PST, but if you're looking for a game right now, we'd like to have you!