Complex sentence: Doitsugaku Kyokai Gakko later became Dokkyo Gakuen, which was founded by Teiyu Amamo, and Minato Seki.
Split into simpler sentences: Doitsugaku Kyokai Gakko later became Dokkyo Gakuen. The new Dokkyo Gakuen was founded by Teiyu Amamo, and Minato Seki.