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.

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. (Source: Wikipedia)

DVD only specials.

That jumbled piece of architecture, that cacophony of hissing steam and creaking joints, with smoke billowing from it as it moves on its own... That castle is home to the magnificent wizard Howl, infamous for both his magical prowess and for being a womanizer—or so the rumor goes in Sophie Hatter's small town. Sophie, as the plain daughter of a hatmaker, does not expect much from her future and is content with working hard in the shop. However, Sophie's simple life takes a turn for the exciting when she is ensnared in a disturbing situation, and the mysterious wizard appears to rescue her. Unfortunately, this encounter, brief as it may be, spurs the vain and vengeful Witch of the Waste—in a fit of jealousy caused by a past discord with Howl—to put a curse on the maiden, turning her into an old woman. In an endeavor to return to normal, Sophie must accompany Howl and a myriad of eccentric companions—ranging from a powerful fire demon to a hopping scarecrow—in his living castle, on a dangerous adventure as a raging war tears their kingdom apart.