Complex sentence: After they leave, Kyoko complains to Noriko that they are selfish and inconsiderate, but Noriko explains that everyone has their own life to lead and that the drift between parents and children is inevitable.
Split into simpler sentences: After they leave, Kyoko complains to Noriko that they are selfish and inconsiderate. Noriko responds that everyone has their own life to lead and that the drift between parents and children is inevitable.