Lapis is the princess of Sorcerland. She's beautiful, powerful and has a sparkling personality; it`s too bad that she's not that bright. She'll go to any length to protect the most innocent of creatures even if it means destroying the kingdom to do so. And lets not forget her obsession with pudding! Detatoko Princess is a laugh-out-loud lampoon of all the fantasy stereotypes you've come to love with a generous heaping scoop of slapstick!

The majority of the Matsuno household is comprised of six identical siblings: self-centered leader Osomatsu, manly Karamatsu, voice of reason Choromatsu, cynical Ichimatsu, hyperactive Juushimatsu, and lovable Todomatsu. Despite each one of them being over the age of 20, they are incredibly lazy and have absolutely no motivation to get a job, choosing to live as NEETs instead. In the rare occurrence that they try to look for employment and are somehow able to land an interview, their unique personalities generally lead to their swift rejection. From trying to pick up girlfriends to finding the perfect job, the daily activities of the Matsuno brothers are never dull as they go on all sorts of crazy, and often downright bizarre, adventures. Though they desperately search for a way to improve their social standing, it won't be possible if they can't survive the various challenges that come with being sextuplets!

In the future, water has covered much of the Earth due to the effects of global warming. The orphaned Maia Mizuki, 15, just graduated from middle school and has already applied for employment in the elite paramilitary Ocean Agency, part of the futuristic world government. Only the best, most intelligent, and physically fit students are eligible for admission. Maia, the series' protagonist, is set to become one of the few. But her ideal life quickly falls apart. To her disappointment, Maia unexpectedly fails her entrance exams. Making matters worse, she promptly gets evicted from her house, pick pocketed, taken hostage, then shot. She is "saved" by two women (Rena and Shizuka) that are part of an unorthodox help-for-hire organization called Nereids (inspired by the Greek mythological Nereids ). With nowhere to go, Maia joins up with Nereids, taking jobs from capturing wanted criminals to chasing stray cats, often with unexpected results. Gloria and Yu later join up with Nereids. "Daphne" in the title refers to a subplot that starts midway into the series and eventually become important to Maia. "Brilliant Blue" refers to the fact that this is a world covered by water with almost no land. The world consists of vast oceans, a few islands, and floating cities.

Two bonus episodes that take place during the course of the series, approximately halfway through it seems. They are entitled 'Everything you always wanted to know about Nereids (but were afraid to ask)' and 'Heaven can wait for Maia Mizuki'. These stories are more lighthearted and comedic in tone, bordering on silly.