I am a romantic, at least when it comes to fashion. So it is easy enough to figure out why I fell head over heels for Otome kei.
According to dailyotome, a Livejournal community:dailyotome, a Livejournal community.
Otome (乙女) means "young lady" in Japanese. Otome-kei (乙女系) is a Japanese street style that focuses on details like bold colors, unusual mixing (but not necessary- can match) of colors, fabric ruffles, embroidery, and ribbons. It can be classified as a substyle of lolita. A lot of the clothing can be used with lolita, but the silhouette is a little different. Petticoats are often unnecessary. The look of otome is romantic and girlish; it can even be described as the more mature version of lolita. Unlike lolita, there are no strict guidelines for this style. Typically, the look one tend to want to achieve with this style is a "refined young lady"; most often, you get the late 1950-1960's feel from the clothes. Some have even called this style as casual OL (office lady) style.
Of course after carefully dissecting many otome style outfits, I came to the my own conclusions.
I would not call otome a substyle of Lolita fashion (another fashion I also indulge in). Otome is a style on its own. If it had to be classified as a substyle I would place it under vintage fashion more than Lolita.
To achieve the look:
Otome kei, or maiden fashion, draws from the fashions of young ladies fashions from 1930s, 1940s, 1950s and 1960s. It has a very innocent look to it, It is wholesome and clean. Simplicity is a must. Jewelry and other accessories should be used minimally. Saddle shoes, oxfords or simple Mary janes (no chunkiness here) would be good footwear.
As for beauty and hair, again simplicity is the name of the game. Simple ribbons tied in a small bow or simple barrettes, or for cooler days a beret should suffice. Make up should be natural and soft, and accentuate the eyes. Lips can be colored with soft pinks or left their natural color with a lipbalm to give them a supple look.