Here are some Rewrite Quest Voice clips detailing Chihaya’s love for lumber.
https://puu.sh/tE5Ci.ogg
z1020_001862
Akane: Chihaya, why are you trying to change your equipment. Your weapon is this piece of lumber.
Chihaya: Why!?
https://puu.sh/tE8EB.ogg
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Chihaya: You know, it would be great if I could have a normal weapon like a long sword.
Kotarou: No, use lumber.
Chihaya: Why does it have to be lumber!?
https://puu.sh/tE8Eb.ogg
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Akane: Hey… There’s a piece of lumber over there. Are you going to get it?
Chihaya: Why are you asking me?