So... Taeko bullied Makoto because she stop focusing her time on her and went with Mitsuru... what kind of fucked up logic is that?!?
Teako forced Rumi to burn the Makoto house down, killing her parents, crippling her sister and she forgave her, telling her to live on?!?
Sure she feels guilty but that's too little, she should confess to police she was the ringleader and made Rumi do the arson.