Hanni and Nanni are not only sisters, but also best friends. The twins are inseparable and always up to something. When they cause a wild chase through a department store, their wealthy parents have had it: They send the girls to the posh boarding school Lindenhof in order to teach them some manners. While sweet-tempered Nanni quickly makes new friends, the impulsive Hanni has a hard time accustoming herself.
| Actor | Role |
|---|---|
| SSophia MünsterHanni Sullivan | Hanni Sullivan |
| JJana MünsterNanni Sullivan | Nanni Sullivan |
 Hannelore ElsnerPrincipal Theobald | Principal Theobald |
 Heino FerchGeorg Sullivan | Georg Sullivan |
 Anja KlingJulie Sullivan | Julie Sullivan |
 Katharina ThalbachMademoiselle Bertoux | Mademoiselle Bertoux |
 Suzanne von BorsodyMrs. Mägerlein | Mrs. Mägerlein |
 Oliver PocherRüdiger Hack | Rüdiger Hack |
 Sunnyi MellesErika's Mother | Erika's Mother |
| ZZoe ThurauJenny | Jenny |
 Aleen Jana KötterErika | Erika |
 Lisa VicariSuse | Suse |
| RRicarda ZimmererKathrin | Kathrin |
| EEmelie KundrunOktavia | Oktavia |
| EEva HaushoferAntonia | Antonia |
| DDavina SchmidLinda Turn | Linda Turn |
 Sophia ThomallaSilke | Silke |
 Monika ManzMutter Hubertus | Mutter Hubertus |
| JJoram VoelkleinDirektor Werner | Direktor Werner |
| FFranca BolengaSophia | Sophia |
| KKevin IannottaMarc | Marc |
| MMaxine GöbelLetitia | Letitia |
| AAmina HeinemannWinni | Winni |