Complex sentence: Although the club still have strong association with Yokogawa Electric, they left the nest in 2003 and started the new life as a non-corporation club under the current name until 2015, when they will carry the name "Tokyo Musashino City" in 2016.
Split into simpler sentences: Although the club still have strong association with Yokogawa Electric, they left the nest in 2003 and started the new life as a non-corporation club under the name "Yokogawa Musashino" until 2015. They will carry the name "Tokyo Musashino City" in 2016.