Okamoto Kauan, Jinguji Yuta, Iwahashi Genki, Hirano Sho - the recent "Sexy Boyz". (Until April 2013 "Sexy Boyz" consisted of Jinguji Yuta, Nakamura Reia, Kuramoto Kaoru and Haniuda Amu. From April until June (in some magazines until August) the members were Jinguji Yuta, Nakamura Reia, Iwahashi Genki and Kishi Yuta - but at times they were announced with a lot more members, too.)
Miyachika Kaito, Abe Aran, Yoshizawa Shizuya, Nakamura Kaito, Kajiyama Asahi - the younger half of "Travis Japan"...
and Shimekake Ryuya, Morita Myuto, Kawashima Noeru, Nakada Hiroki - the older half of "Travis Japan".
Morimoto Shintaro, Tanaka Juri, Kochi Yugo. For more about Morimoto Shintaro see here: morimotoshin!
Hagiya Keigo, Yasui Kentaro, Kyomoto Taiga. For more about Hagiya Keigo see here: hagiya_keigo! For more about Yasui Kentaro see her: yasuikentaro! For more about Kyomoto Taiga see here: kyomototaiga!
Matsumura Hokuto and (Lewis) Jesse. For more about them, Taiga, Yugo, Shintaro and Juri please check bakaleya6!
Nozawa Yuki and Sanada Yuma, "Noon Boyz".
Fukazawa Tatsuya, Miyadate Ryota, Iwamoto Hikaru, Watanabe Shota, Sakuma Daisuke, Abe Ryohei - "Snow Man". More about them can be found at mis_snow_man!
Fukuda Yuta, Matsuzaki Yusuke, Koshioka Yuki, Tatsumi Yudai - "4U". Please check mix_madmade for more about the dance umbrella boys!
Next the Kansai faction (young to old) [more about them can be found at kansai_juniors]:
Yamasaki Kunta, Muro Ryuta, Hamanaka Bun'ichi, Kikuoka Masahiro - "Veteran".
This list is of course not complete, there are many more around, but if there is someone who caught your interest (or you think someone very important is missing etc.), please feel free to contact the mods and/or request translations :D