all the styles i know of.. there might be more..
Visual Kei: Literally, "Visual Style". Term used to describe bands who focus on image/costumes, such as Malice Mizer.
Angura Kei: Literally, "Underground Style". Term used to describe bands who have generally darker themes and a distinct traditional Japanese style, such as Inugami Circus-dan.
Oshare Kei: Literally, "Fashion-conscious Style". Term used to describe bands with a cute and colorful fashion style whose sound usually matches the visual, such as Psycho le Cemu.
Eroguro: Short for "erotic and grotesque". Term used to describe bands whose themes are centered in shocking horror and bizarre sexual imagery with dark humorous overtones, such as Cali≠Gari.
Indies: A band that isn't on a major label.
lolita: a doll like style there are many different sub fashions of lolita.
decora: is a colourful miss matched style. sort of like a more wilder version of oshare but with many assessories and off the top styles.
ganguro: a style where japnese girls dye their hair blonde with many other colours. they have tans, coloured contacts. and wear white makeup around their eyes, no one really knows the origin of this style but it is like a hyper version of the "californian surfers"
kogal: is a preppy like style, more elegant and less off the top, has a professional look.