A Supporting Character Who Doesn't Steal the Show Isn't a Good Supporting Character

An ordinary girl is forced by Kyubey to sign a contract and become a magical girl. Just when she thinks Kyubey will oppress her for the rest of her life, she discovers that Kyubey is actually an industry conscience across the infinite worlds. The missions are easy (she only has to show her face while the protagonists fight bosses, and there's no penalty for failing), and she even gets a powerful protector as a bonus (being invincible among those of the same rank is a given). With Kyubey's indulgence, the protagonist goes ever further down the path of courting death. This is a single-girl yuri story. If you see the protagonist flirting with male characters, it's all an illusion. Volume 1: A Certain Magical Index. Volume 2: Naruto (Many readers say it seems to involve gender-bending and fawning over the Uchiha. If you don't like that, just skip it.) Volume 3: Date A Live. Volume 4: Akame ga Kill! Volume 5: SEED. Volume 6: A heavily revised ending that can still be saved. You can read each volume separately, since every volume tells a standalone story.