Okay, so I have created special ranks for the site. "Rank" might not be the right word for them, as they are more like groups. Even if you create a character in these groups, you will be able to do other things and you'll get a normal rank. The point is, if you join one of these groups, the Hokage might summon you to work and you'll get more chances to RP.
Academy teacher (Chuunin, Special Jounin or Jounin)
Medic (Chuunin, Special Jounin or Jounin, must have Medical Ninjutsu as a main specialty)
Konoha police officer (Special Jounin, Jounin or ANBU)
Hunter-Nin (Special Jounin, Jounin or ANBU, usually Medical Ninjutsu as a specialty)
Interrogation (Special Jounin, Jounin, or ANBU)
Group explanations
Academy teacher
Ninja who sometimes or regularly work as teachers at the Academy, teaching ninja students and keeping discipline. May be summoned to work, but never urgent.
Medic
Ninja who are trained in medical skills. They may either be assigned on dangerous missions for support, or they might work at the hospital. May be summoned to work, usually urgent.
Police officer
Ninja who devote their time in the village to keeping peace and solving crimes. They might also have to work as freelancer guards, stopping ninjas from escaping the village. ANBU usually work like a real-life SWAT team, completing the most difficult or stealthy missions. May be summoned to work, usually urgent.
Hunter-Nin
Ninja who hunt down escaped ninjas to stop them from joining organizations or spreading secrets of the village. If the police fail to stop a criminal from escaping, the Hunter-Nin are assigned to the job. Medical training is useful, as Hunter-Nin often have to completely dissolve of bodies to hide them. May be summoned to work, usually urgent.
Interrogation
Ninja who specialize in forcing information out of captured criminals. On less urgent cases with minor criminals, they will only use brainwashing and mental pressure, but if the criminal is very dangerous and the case is important, they might also use physical torture. Maybe summoned to work, sometimes urgent.