Let's see, so Shanghai just had a cold? That means Alice is using Hourai today, and Hourai is stronger, take that into account.

It's Ash Wednesday, but we're in Japan so nobody cares. It is Wednesday though, so everybody is at their peak, because Wednesday is the middle of the week.

Now, assume each star needs X amount of damage to be broken through. Since it's 1 star thick, but they're big stars, x is obviously an enormous number.

Alice's lasers are weak, even at 4.7 power. We all know she relies on Malice Cannon to not be the worst character ever conceived, so take that into account!

Now, Marisa dropped her hat, which will just make her more mad, even if her head is colder, so the stars increase in power. This means it's like 2x to break through a star, which is indeed a huge difference.

Alice is being tsundere, so her power is actually lower. Like 4.5. This is probably a good thing for Marisa.

Tsundere does last for a long time though, but if you look at Alice's hourai beam in IaMP, where imaginably she was doing quite well because she was very well fed, it's really not that long of an attack. Let's say a star has 75 HP normally, so it has 150 now. I think this is reasonable with Marisa's familiars in her IN attacks.

I will take 4.5 to mean damage per second, each hourai beam lasts two seconds. She can have up to 9 power bars, going by IaMP's rules, and maybe she has a secret spellcard hiding that can do 20 damage.

Unfortunately, since Marisa lost her hat, there is a 0% chance that Alice will win.

But wait! Let's say there is a 30% chance that Reimu will stumble upon this battle. There is also a 75% chance that Reimu is mad at Marisa and would rather help Alice than Marisa. Therefore, Reimu will obviously put the hat back on and suddenly, Marisa will eat laser. 26 damage if the secret spellcard is used, 6 if not.

The consequences are probably pretty small. Alice will feel bad and make up for it anyways, so what does it matter? But in the end, a 22.5% chance of her winning isn't bad. Yay.