Complex sentence: A relative of Tarō's, his family being a branch of the Komori's, he has O.B.Es like Tarō and Masayuki, and is able to produce them while playing his guitar, a regular pastime of his.
Split into simpler sentences: A relative of Tarō's, his family is a branch of the Komori's. Makoto experiences O.B.Es like Tarō and Masayuki, and is able to bring the experience on while playing his guitar, a regular pastime of his.