Complex sentence: In 1928, he became a captain in Japanese cruiser Natori and in 1929, he was a captain in Japanese cruiser Ashigara in 1930, he became a teacher at the Naval school.
Split into simpler sentences: In 1928, he became a captain in Japanese cruiser Natori and in 1929, he was a captain in Japanese cruiser Ashigara. In 1930, he became a teacher at the Naval school.