Spring Weapon Number One

An evil organization of androids called Numbers is threatening to take over the world! Luckily, a top secret defense force of specially trained operatives called MAPPO (Monster Attack Professional & Pacific Organization) is there to stop them. So what happens when a MAPPO agent in high school gets a new classmate that's a wacky-looking Number?

(Source: VIZ Media)

Included one-shots:
Volume 4: Saishuu Heiki Kon-chan
Volume 5: Shimatsuya K