Yoku Wakaru Gendai Mahou: Cruncha Cruncha Cruncha

An extra episode which takes place in the middle of the TV series. Yumiko thinks that Misa isn't teaching Koyomi magic properly, since Koyomi can still only summon washbasins. Yumiko decides to teach her Classical Magic, since Misa's teaching of Modern Magic doesn't seem to be helping Yumiko. (Source: Wikipedia)