Zakrytaya shkola (2011)

in this TV series there is a school and in that school have been many secrets, students from this school find out that a teacher has gone missing so they start to look for him this then leads into a long journey which gets into a difficult situation where it's hard to escape from (season 4 and I think season 3). At the end many things get revealed and the series comes to an end. This TV series is very emotional and funny at the same time.