Ok, so for those wondering if Takeda-sensei remains a child or not. Most of the time he does but when he eats this snack he's able to transform to an adult so before they get to do the do, he'll eat it.
In the author's note, Chikadoh mentions an extra/omake(?) from the manga where I think the characters are depicted as tiny children like Takeda in this DJ so I guess she wanted to draw it too.
Ok, so for those wondering if Takeda-sensei remains a child or not. Most of the time he does but when he eats this snack he's able to transform to an adult so before they get to do the do, he'll eat it.