Natsu is the older sister of Takaaki Ishimaru, and the mother of Gundham Tanaka. She is a nurse at a children's hospital and she is a kind, upbeat lady who tries to smile as much as she can. She is a horrible cook. She hates her father for abusing her and her brother. She refused to let her father live with her after his scandal. She has also raised Gundham alone as her husband left. She is good at adapting, but carries deep grudges. She loves most of her family though.