The Hanabishi and Hidaka families live next door to one other.
Because the dads of both houses are close friends, they get along like one big happy family. The four Hanabishi sisters, in particular, fostered the Hidaka family’s only son Kouki as if he were their own brother.
The Hanabishi and Hidaka families were planning a long-term international business vacation together one day. Kantaro Hanabishi’s only reservation about the trip was leaving his four daughters behind in Japan.
“I’ll take care of it.” You can count on me to keep an eye on them!”
Both parents gladly left on their trip as a result of Kouki’s casual statement.
“How dependable!” That’s exactly what I needed to hear!”
They had arranged for one of the four sisters to be Kouki’s fiancee between the two parents.
They planned to discuss it further after Kouki’s graduation, but this recent event provided an opportunity to move on with their plan.
As a result, Kouki will spend his summer vacation alone under one roof with all four Hanabishi sisters.
Yurina, the eldest daughter: Despite being competent at her job, she is a slacker at home and makes Kouki work hard.
Momone, the second-born daughter, adores Kouki and does nothing but spoil him.
Saori, the third daughter, performs all of the cleaning and, despite being a maid, prefers it to going outside.
Anzu, the youngest daughter, has no reservations about referring to Kouki as her own plaything.
Each of them has their own motivations for doing anything they can, even luring him into sexual situations, in order to get closer to becoming the Kouki they adore.
Who will Kouki choose as his bride if he ever does?
The action-packed existence with the four sisters is about to begin.