The ones harassing Riko and her friends were "former" student council president Enomoto Yuiko (Eno), whose work was stolen by Maki, and her friend and student council treasurer Mizushima Sayori (Sayo). Declaring war on Riko and her friends, Eno and Sayo sneak into the student council room where they discover materials related to the love lab.
Meanwhile, Maki takes on all the responsibilities of the student council herself and collapses from the strain...
I returned to the student council 
because I worry about the budget.
Regresé al consejo estudiantil porque 
me preocupaba por el presupuesto.
He vuelto al consejo estudiantil porque 
me preocupaba por el presupuesto.
Je me faisais du souci pour le budget,
 donc j’ai décidé de retourner au conseil.
Eu voltei ao conselho pois estava 
preocupada com o orçamento.