Koyomi, a naive and childlike figure, wishes to change herself! She begins to learn modern magic from Misa, the strongest magician. However, Koyomi's magic activates strangely, causing monsters from another world to appear. Around the same time, bizarre occurrences start happening across various places due to network magic! Koyomi's adventure to solve these incidents begins, teaming up with the genius magical girl Yumiko and the high school girl Kaho, who excels in computers!