Hikkatsu!: Strike a Blow to Vivify (2005)

Blurb:
In Earth’s distant future, geomagnetic abnormalities make every day a struggle to survive. The human race faces its greatest threat—not from aliens, meteors or global warming, but ordinary, every day appliances! With even the most basic of machines going haywire, one man holds the hope of Earth in his hands: karate student Shota, who can beat any appliance into submission with his Repair Blow! Shota is joined in his adventures by the sweet and spicy Momoko, and the street-smart con man Kanji, who each have their own reasons for sticking with the dilligent karate student. Whether it’s to chase true love, or make an easy dollar, these two will stay by Shota’s side through thick, thin and marauding household machines!

Source: www.anisearch.com/manga/4160