Surprisingly, this is a shoujo manga. I guess I was captivated by the title which resemble the serious action manga, Full Metal Alchemist. But, they are definitely unrelated.
Sousuke, a machinery maniac, swears of protecting his friend Chidori Kana with all he’s got. He can crash the window after hearing her voice (even though it was just a cockroach), blow her shoes box to prevent bomb ( he thinks someone has approaches the locker before her), or snap a knife to a teacher who scolds her. Ha ha ha
It’s hilarious! I would have read it earlier if I knew.
I got it from manga-download