The Yoshimoto family currently consists of an older sister, Nene, and a younger brother, Masamune. Masamune is pushed around by his sister, who is a beautiful woman and does her job well but has no life skills at all, but his younger brother is also quite clever. Today, they are enjoying their bumpy life together.

Continuing on the story of the Obinata household, the focus this time is on the two youngest members, Yuuta and Mayumi.

Peace seemed to have finally found its way into the Obinata household, but through an unexpected turn of events, Shuu and his adopted son, Yuuta, are faced with a disagreement that might change their lives forever. When their respective lovers – the eldest Obinata brother Taiga and Mayumi, the youngest brother – are dragged into their conflict, and Yuuta runs away from home, the whole family's living arrangement gets off balance. Will the peaceful days ever return?

After Yuuta and Shuu reconcile and the children return home, new trouble is on its way. This time, said trouble involves the quiet second eldest brother, Akinobu, and the hot-blooded head of the house, Taiga.

This time, the focus is on the second eldest brother in the family from Mainichi Seiten — the bespectacled Akinobu who wakes up one morning in an unfamiliar bed with someone most familiar and unexpected.