This is speaking from my own carelessness experience:
Always be careful when handling bamboos! They have those tiny thin little dark splinters on the surface of its skins in between the joints! Those splinters might sticks to your hand and its painfully stings/itchy! So please make sure to wear a glove—a cloth glove will do—unless you dont mind to bear those splinters!
Also, the way ponko holds the bamboo when yuuna tried to split them is wrong! Dont—ever—hold them from the bottom! Dont! Just—dont! Instead, hold them from the top as you split them all the way down!