Troublesome childbirth sex by 4 classmates ZUKO-070

You have four close female classmates. They all like you. They pretend to be sick and leave school early, then secretly visit you during lunchtime, giving you no time to rest. They've received protective medical treatment, broken their friends' promise to have sex, and everyone even went into the bathroom to "cure" you. They even sneaked into your house at night out of fear... It all turns into a harem battle for you...