Sayuri Haruno is a girl who attends an elite confectionery school Fleurir on a scholarship. She attends the school to follow her dream to open a pastry shop. In her school, she meets several charming young men.

Yona is the sole princess of the kingdom, living the luxurious and carefree life as a princess should. She has it all: the finest clothes and cosmetics, the most divine sweets, a loving emperor as a father, and the hottest cousin crush, Soo-won, anyone could ever hope to have. Now, if only her bodyguard, Son Hak, wasn't so annoying to her and her hair wasn't so red.

Tatsumi is a high school boy who lives by himself. However, a devastatingly handsome merman named Wakasa moves into the bathtub in Tatsumi's home. Wakasa is a bit self-centered but cute, while Tatsumi is cool but a busybody.

Erika Shinohara, a vain 16-year-old girl who tells her friends about her romantic exploits, is actually has no boyfriend. She claims that a handsome boy in a candid photo is her boyfriend, but it turns out that boy is a schoolmate named Kyouya Sata. She has no choice but to make him her fake boyfriend. Unfortunately, Sata may look like a sweet person, but he is actually an ultra-black-hearted sadist. Sata takes advantage of Erika's weakness and treats her like his dog.

In the eleventh year of the Meiji era carrying swords was forbidden by the government and those known as samurai were slowly fading away; however, there were plenty who didn't like those changes taking place in Japan and inevitably the crime rates increased. The country's only solution was an inescapable lake prison. Since the prison had no other way to access it except by water, the three boys of the Kumo family were assigned to transport the criminals to their new "home." Although, is that the only thing they were doing...?