So, completely unrelated, but I've been playing Drift Spirits and wanted to talk about the way their events work. It makes me really appreciate OP having the transponder snails and the potential for a stamina overflow. Here's the gist:
Your stamina is in the form of fuel, which goes up by leveling and adding friends. Raising your car's affinity level by using it often can lower the amount of fuel required per race, and there's also a car part you can install to lower it greatly, which can be upgraded. You feed parts to other parts, like your team members in many other games.
Each race requires x amount to go. My current fuel is 2360, and my car requires 451 per race, so I can crank out 4 races per bar without waiting for it to refill. But when you race a boss character, it requires 2x fuel, which is 902 in my case. So I can do two of those and then I need to wait.
You can refill your fuel with tanks that either refill a half-tank, or an entire tank. But those are infrequent rewards for races, so they are nice enough to let you buy them for real money (I haven't let myself do this yet, heh.) It also refills over time, to the tune of 10 fuel per minute, or 600 per hour.
So right now, there's an Initial D event where you can race against those characters, and their cars are potential drops. But they don't just appear. First you need to do a race of any sort, then an Initial D person will come out. The first one is Takumi. In order to get past him, you need to beat him in 3 forms: regular, determined, and... I think it's called fired up. The first few races are against the regular form, then the determined one, then there's a random race in that slot against one of three girl allies you have (this lets you get an item, one of which is a half-tank refill), then if you're lucky, the fired up version comes out. So you're talking at least five races against the character, or at least this is how it seems to work. There don't seem to be many good resources for this game around, so this is just my experience.
But where they get you is, it's timed. Not like "turtle time is for 1 hour" or "brook is here for 14 days." You win an event race, and then it says a specific time until it expires. So like right now, I have until 13:58 to race this dude with a yellow RX-7, in his determined form. If I miss it, it resets. I don't think it resets to the first character, because I'm on the second one, but it will reset to the initial version you race. It feels like a way to manipulate you into buying gas, but I won't! You won't get me, game!
So I guess what I'm saying is, pulling a stamina restore in OPTC is a pretty great thing and other games should adopt this.
[edit - it recharged to 902 at exactly 1:58. I beat the guy, now the next race is another 902, but it times out in 30 minutes. Sorry, game. Not gonna sucker in.]