Complex sentence: Upon emerging from the temple in 2001 he began to teach Aikido both in Japan and internationally, aikido instructors from many countries joined Maruyama's new association and it grew rapidly over the course of the next ten years or so.
Split into simpler sentences: Upon emerging from the temple in 2001 he began to teach aikido both in Japan and internationally. Aikido instructors from many countries joined Maruyama's new association and it grew rapidly over the course of the next ten years or so.