Complex sentence: Mokuami was born in the Nihonbashi district of Edo (modern-day Tokyo), and at the age of 20, entered into an apprenticeship and in 1843 became the standing playwright for the Kawarazaki-za theatre.
Split into simpler sentences: Mokuami was born in the Nihonbashi district of Edo (modern-day Tokyo). At the age of 20, he entered into an apprenticeship and in 1843 became the standing playwright for the Kawarazaki-za theatre.