\begin{tikzpicture}

    \newlength{\YShift}
    \newlength{\XShift}
    \setlength{\YShift}{0.8\base}
    \setlength{\XShift}{0.8\base}

    \tikzstyle{modelnode} = [rectangle,draw,rounded corners=2pt,inner sep=0pt,minimum height=4.2em,minimum width=2em,font=\small,anchor=north]

    \coordinate (stu01) at (0,0);
    \coordinate (stu02) at ([xshift=3em]stu01);
    \coordinate (stu03) at ([xshift=3em]stu02);
    \coordinate (stu04) at ([xshift=3em]stu03);
    \coordinate (stu05) at ([xshift=3em]stu04);
    \coordinate (tea01) at ([xshift=8em]stu05);
    \coordinate (tea02) at ([xshift=3em]tea01);

    % iterations
    \foreach \curr / \prev in {1/0,2/1,3/2}
    {
      % models
      \node[modelnode,fill=yellow!20] (stu\curr1) at ([yshift=-2em]stu\prev1.south) {\rotatebox{90}{Student $1$}};
      \node[modelnode,fill=yellow!20] (stu\curr2) at ([yshift=-2em]stu\prev2.south) {\rotatebox{90}{Student $2$}};
      \node[modelnode,fill=yellow!20] (stu\curr3) at ([yshift=-2em]stu\prev3.south) {\rotatebox{90}{Student $3$}};
      \node[modelnode,fill=yellow!20] (stu\curr4) at ([yshift=-2em]stu\prev4.south) {\rotatebox{90}{Student $4$}};
      \node[modelnode,fill=yellow!20] (stu\curr5) at ([yshift=-2em]stu\prev5.south) {\rotatebox{90}{Student $5$}};
      \node[modelnode] (tea\curr1) at ([yshift=-2em]tea\prev1.south) {\rotatebox{90}{\color{red!60} Teacher $1$}};
      \node[modelnode] (tea\curr2) at ([yshift=-2em]tea\prev2.south) {\rotatebox{90}{\color{blue!60} Teacher $2$}};

      % ensemble labels
      \draw[-latex'] ([xshift=2pt]stu\curr5.east) to node [auto] {\small Ensemble} ([xshift=-2pt]tea\curr1.west);
    }

    % iteration labels
    \node[font=\small,anchor=east,purple!80] (iterate1) at ([xshift=-1em]stu21.west) {\rotatebox{90}{Iteration $1$}};
    \node[font=\small,anchor=east,purple!80] (iterate2) at ([xshift=-1em]stu31.west) {\rotatebox{90}{Iteration $2$}};

    % distillation labels
    \node[font=\small,anchor=south west] (distill1) at ([yshift=0.2em]iterate1.north west) {Distillation};
    \node[font=\small,anchor=south west] (distill2) at ([yshift=0.2em]iterate2.north west) {Distillation};

    % student groups
    \begin{pgfonlayer}{background}
      \node[rectangle,draw,very thick,red!60,densely dotted,inner sep=2pt,rounded corners=2pt,fill=red!20] [fit = (stu21) (stu22) (stu23) ] (group21) {};
      \node[rectangle,draw,very thick,blue!60,densely dotted,inner sep=2pt,rounded corners=2pt,fill=blue!20] [fit = (stu24) (stu25) ] (group22) {};

      \node[rectangle,draw,very thick,blue!60,densely dotted,inner sep=2pt,rounded corners=2pt,fill=blue!20] [fit = (stu31) (stu32) ] (group31) {};
      \node[rectangle,draw,very thick,red!60,densely dotted,inner sep=2pt,rounded corners=2pt,fill=red!20] [fit = (stu33) (stu34) (stu35) ] (group32) {};
    \end{pgfonlayer}

    % distillation
    \draw[-latex',red!60,very thick] (tea11.south) .. controls +(south:1.5em) and +(north:2em) .. (group21.north);
    \draw[-latex',blue!60,very thick] (tea12.south) .. controls +(south:2em) and +(north:1.5em) .. (group22.north);

    \draw[-latex',red!60,very thick] (tea21.south) .. controls +(south:2em) and +(north:2.5em) .. (group32.north);
    \draw[-latex',blue!60,very thick] (tea22.south) .. controls +(south:2em) and +(north:1.5em) .. (group31.north);

  \end{tikzpicture}