Diseases are defined by their virulence, from 0 (harmless) to 10 (bacteriological weapon level deadly.). When a disease starts breaking out, characters need to make Fitness checks to avoid catching it ([Homebrew] magical girls get a +2 bonus to it [/homebrew]). They suffer from a penalty equal to the disease virulence to that roll. They can gain bonuses to their Fitness checks by being careful, which includes any actions to try to avoid catching the disease (up to and including wearing a gas mask and not removing it even for sustaining oneself (yes, it is possible to drink with a gas mask on. So if you're willing to only eat liquid food (like soup), it's possible.)). On a roll of a natural 1, the character is even immune to the disease.
When catching the disease, you lose as many health points as the disease virulence, and suffer that value as a penalty to all your checks, except those made for recovering.
Each day after the initial contagion, you make a fitness check ([Homebrew] magical girls get a +2 bonus to it [/homebrew]). You can gain bonuses if you get medicine or a trip to the hospital. If you succeed, you start getting better. [homebrew] You recover 1 hit point and cancel one point of penalties for each 12 hours period afterward [/homebrew] (non magical girl do the same, but for each 24 hours period), until you fully recover.
If you fail, you lose one more HP, and you will have to try again the next day.
[Homebrew] You have a number of stamina points equal to Fitness *2 [/homebrew] (non magical girl have only Fitness points)
If your girl gives all she has and makes a tremendous effort, she can increase her chances of succeeding at an action by 1 point (this include fighting and dodging). You must then roll 1D10: If you get a result under your current stamina point, you lose one stamina point and get a +1 bonus to your action. If you roll above your current stamina, you lose 2 stamina points, but still gain the +1 bonus.
If you get to 2 or less stamina points, you can doze off in class if you fail a Fitness check. [homebrew] Not having a full night of sleep (8 hours) gives you a -1 point penalty to your stamina score for the day per hour you missed. [/homebrew] For each hour of rest, you recover one stamina point, then you need to make a roll: if you roll under your current stamina points, you recover as many stamina points as your success margin. For every HP you lose in the critical wound range, you also lose one stamina point.
And last: Experience: You don't gain XP. Instead, you can increase your mastered skills and powers, master new skills and powers, and change your traits.
Increasing skills and powers: If you try to use a skill you have mastered, put an easily recognizable symbol near it. Normally, if you have 3 of them on the same skill at the end of a session, you can roll to try to increase that skill. Since the idea of a gampe session is a bit shaky when on a PBF format, if you have 3 symbols near a mastered skill, at midnight, France time, this roll will happened. If 1D10 rolls above that skill or power, it's value increases by 1. The three symbols on that skill are erased after the roll, whether the increase happened or not.
Mastering a new skill/power: After practicing it and finding a teacher, you must make an Intelligence check. Success means the penalty is reduced by one if different from 0, and the skill is considered mastered for the purpose of increasing it later. If you try to master a new power, you get it at a level equal to your success margin (min 1).
Last, you can add or remove traits after a while. Depending on your life experience, and intense emotions your magical girl experienced or created in others, you gain emotional experience points. You can spend 50 emotional experience points to add or remove a trait, if you can find a reasonable reason for it. People let go of their hurdles, or gain new ones all the time after all.