I thought it would end with sensei together and not Mamura. Because I thought she would mature through high school together with Mamura and than would get together with sensei. Through the whole manga I had the feeling that the maturity of sensei and Yosano was not the same so them really being together would be weird. But Mamura had the same level of akwardness.. so they fit quite good. Anyway, I am happy with the ending. Especially because it shows how real lifes love changes with the commitment of people. Mamura was there for her from the beginning and Yosano started to understand that and fell in love with the person who deserved her the most. Aaah... this is soooo long! Sorry, I am a bit drunk right now..
spoiler
I think there was no real good ending that would have made me really happy because I love sensei and mamura, they both have their good and cute traits but I kind of thougt that she would end up with sensei and tried to accept it although I liked mamura way more (he's sooo cute!!!!). So in my opinion an open ending would have been better but it would also frustrate me as hell. The end with mamura is cute but I am kind of dissatisfied. Another question how much did suzume spend for the train rides from okinawa to tokyo and back??