I cant find any right sized pics of Kou Shibasaki ('Hardcore' Mitsuko Souma) anywhere

The special edition explains her story better. Basically, her mother was a drug addict and theres an extra scene where she tries to 'sell' Mitsuko to a dodgy looking bloke. However, when he tries to make his move on Mitsuko, she pushes him and he falls down a set of stairs, killing him

One of the most important scenes in the film, as it explains why she says "Why am I always the loser?" after she is taken out by Kiriyama.
Earlier, when she takes her second victim, Hirono Shimizu, Hirono yells "You were pimping Yoshimi". The comic book explains better that Souma, after her experiences and being prostituted by her druggie mother, (Hirono) Shimizu, (Yoshimi) Yahagi and another girl were a small gang. Souma has no qualms about seducing rich men and stealing from them, in one case killing him in the process. She became outwardly a strong girl, but inwardly feeling alone after her abuse. This explains her psychopathy - she is killing her classmates who she feels have never accepted her and always hated her.
In the comic book, she does (kinda) pimp Yoshimi - she arranges sex between her and a guy, only telling her afterwards that it was for money. However, Yoshimi then falls in love with the guy so its not quite the same thing. How does Yoshimi die? She was the one found hanged with her boyfriend (Yoji Kuramoto) by Souma just before she slits Megumi Eto's throat in the toolshed. Note her disregard when she says to Hirono "I saw Yoshimi and Yoji hanged outside. How noble."
There is an amazing and in depth story behind Battle Royale which takes it past being just a film to being a masterpiece
