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

As a part of the JUMP START initiative, the first three chapters of Spring Weapon Number One published in English in VIZ Media's digital Weekly Shonen Jump on the same day as the Japanese release.