Complex sentence: When she encounters a popular boy named Yamato Kurosawa he becomes interested in her, and it is through their tentative friendship and blossoming relationship that Mei ultimately begins to branch out and befriend others.
Split into simpler sentences: When she encounters a popular boy named Yamato Kurosawa. Yamato he becomes interested in her and it is through their tentative friendship and blossoming relationship that Mei ultimately begins to branch out and befriend others.