The US DVD includes an Inu-Yasha no Tsubo special as an extra. The Inu-Yasha no Tsubo segments typically run after episodes that air in Japan as a commericial break eyecatch. This special, however, introduces the lead characters and storylines of Inu-Yasha.
The battle between Inuyasha's father and Hyouga over the Sea of Japan was so fierce that it caused the tremendous storm "Kamikaze" which thwarted the invasion of Japan by Hyouga and his human allies.
Ruri didn't know about the Wind Tunnel until Miroku uses it to kill the scorpion. So she didn't know it was a terminal curse meant to kill the user eventually. So it makes sense she didn't know cutting her copied version wider would only hasten her death. Making matters worse is that she allowed her spear to get swallowed into it. If she still had it, she could have cut off her hand right when the Wind Tunnel went critical.
This is the only movie to hand drawn. The succeeding movies were all done digitally.
This is included on the' Inuyasha the Movie: Affections Touching Across Time' DVD as a extra feature.