まるです。

「む、これはもしや――」
Maru:[ This is my toothbrush. ]
呼ばれて走ってきてみたら歯磨きの時間だったので、とても微妙な顔をしているところ。
Maru came running because I called his name.
However, he noticed that it was time for toothbrush.
Therefore he looks slightly serious.