Shinpei Natsuki is an ordinary high school student, with an extraordinary new housemate, UFO-chan or Yuha Maria, a foreign Space Officer on a mission to thwart rogue alien species from attacking planets. Shinpei reluctantly accompanies Yuha on frequent time-travel trips in her UFO to protect the future from alien takeover, with his memory getting wiped to preserve Yuha's secret identity.
The bottom strip titled "Professional" features a hitman sent to eliminate the mob boss Calpis Soda, with several comical incidents during the mission.
