Simplify the following text for a Grade 9 native English-speaking person.
Original: At this time , Sergei studied Japaneseâ '' he learned some three hundred kanji characters which he cited as an influence on his pictorial development , and gained an exposure to Kabuki theater ; these studies led to travel to Japan .
Simplified: At this time , Sergei studied Japanese . He learned some three hundred kanji characters which he cited as an influence on his pictorial development .