Asahi, Hikari, Haru and Tadashi are siblings that all live together in the house they grew up in located in Shitamachi. There is another brother, Satoru, but due to something that had happened in the past, he had moved out. Their parents had died when they were young, and Asahi, being the eldest, is the one who had taken care of them all. Asahi is a conservative, stubborn man, and his favorite phrase to his siblings is, "I am the one who had brought you all up", which irritates them no end.
Asahi works at a construction site and goes to a shop daily to buy lunch, where he meets the shop's cute employee, Sawabe Asuza.
Hikari works as a nurse in the Newborn Intensive Care Unit (NICU) at the hospital, together with the family friend who used to live nearby, Dr. Shinjo Masaomi.
Haru doesn't like to study, and prefers to tread the boards instead. As the head of his performing troupe, he is a temperamental man who fusses over the troupe members.
Tadashi is currently under suspension from school, so in order to not fall back on his studies, he is currently attending a prep school daily. At the prep school, he is drawn to another fellow student, Nagihara Kasumi.
As for Satoru, one day, in her workclothes and smoking a cigarette, Yashiro Takako suddenly calls out to him, "you killed your mother, didn't you?"...
Five siblings, each with their own problems, soon find themselves in various situations, living life as a youth of today.