Complex sentence: After transferring to prestigious East Matsuyama High School, he was known to be intelligent enough to read Rimbaud in French, but due to his poor academic record, he had to remain in the same class for two years.
Split into simpler sentences: After transferring to the prestigious East Matsuyama High School, where he was known to be intelligent enough to read Rimbaud in French. But due to his poor academic record, he had to remain in the same class for two years.