Mayuko Iwasa

Mayuko Iwasa (岩佐真悠子) (born February 24, 1987, in Nerima, Tokyo, Japan) is a Japanese entertainer/model. She was Miss Magazine 2003 and made an impact in various Japanese magazines as an early-blooming high-school girl. Iwasa was awarded the Graph Prize, the 42nd Golden Arrow Awards (2004) in March 2005.
In June 2005, Iwasa recorded a duet with Naoya Ogawa called "Katte ni Shinryakusha" (An Invader in My Own Way), which was used as an ending song of Sgt. Frog. The two appeared on Music Station and Pop Jam. Iwasa was recently^[when?] in the drama Gal Circle as Rika, a ganguro who scams her friends for money.

Reference: Wikipedia

Masami Nagasawa

Masami Nagasawa (長澤 まさみ, Nagasawa Masami, born June 3, 1987 in Iwata, Shizuoka) is a Japanese actress.

Nagasawa was chosen to star in a movie called Gunjo, based on a novel by Ayako Miyagi and directed by Yosuke Nakagawa. It is the second Japanese movie produced by 20th Century Fox. Filming finished on August 5, 2008 and includes her first actual love scene. It was to be released in spring 2009, although Fox aimed to have it premier at the Berlin International Film Festival in February.
She and Odagiri Joe starred in the TBS drama, Boku no Imoto. They played siblings.
On October 20, 2009, Nagasawa starred in a movie titled Magare! Spoon. It premiered at the Tokyo International Film Festival. In the film, she plays a clumsy assistant director of a TV show about the paranormal, unaware that the cafe she is stranded at on Christmas Eve is the location for an annual gathering of men with psychic powers.
To celebrate its 50th anniversary in 2010, Fuji TV announced a major television drama special: Wagaya no Rekishi. The story takes place between 1945 and 1964, chronicling the lives of the seven members of the fictional Yame family. Nagasawa is among the cast members. The drama will air on three consecutive nights during spring 2010.

Reference: Wikipedia

Manami Oku

Manami Oku (奥真 奈美, Manami Oku, born November 22, 1995 in Tokyo) is a Japanese singer known for her work in the Japanese idol group AKB48. She belonged to the "Team B" as a subset of the members of AKB48 Honegumi, She is of Italian origin.

Manami Oku was the youngest member of the group, which started in 2006 with the team K, and she participated in the temporary group AKB48 Honegumi in 2007. She is the third member to have released a solo single in a parallel group. In 2010, the group name changed to Manami Ogu (おぐま なみ, Ogu Manami?), which serves as the ending theme of the anime series Ojarumaru (おじゃる 丸?). In February 2011, she expressed her desire to leave the group to continue studies. Final departure came into force on 8 April 2011.

Reference: Wikipedia

Maimi Yajima

Maimi Yajima (矢島 舞美, Yajima Maimi, born February 7, 1992 in Saitama Prefecture) is a member and the leader of Cute, a J-pop group within Hello! Project. Her younger cousin, Akari Takeuchi, is a member of S/mileage, another girl group within Hello! Project. She has been nicknamed "Rain Girl" by fans and her fellow Cute members, who say that she is the one that causes it to rain so often on important days, such as at concerts and events the group attends.

Yajima first joined Hello! Project in 2002 as one of the fifteen children chosen from the Hello! Project Kids auditions after performing "Momoiro Kataomoi" by Aya Matsuura. She debuted the same year in the movie Koinu Dan no Monogatari, taking on one of the main roles as an antagonist. The following year, she joined the first of the kids' groups, ZYX, which released two singles.
In 2004, Berryz Kobo was formed, with the intention of rotating the girls throughout the unit. Yajima did not make the original pick, and the idea was eventually dropped. The remaining girls eventually ended up forming Cute in 2005. Despite not being the oldest, Yajima still became the group's leader, after Erika Umeda turned down the role. The group did not make its official debut until late in 2006, with their first official single released in February 2007.
Aside from leading Cute, Yajima is also the sub-captain of Little Gatas, the Hello! Project Kids futsal team. She is also considered to be one of the fastest runners in all of Hello! Project, often coming first in the running events at the annual sports festivals and listing running as one of her hobbies.
Yajima also co-hosts Cute's weekly radio program, Cutie Party. She took over the role when Megumi Murakami left the group.
In 2008, Yajima was selected to be a member of Hello Project's new unit High-King. Yajima and Fukuda Kanon appeared in the movie Fuyu no Kaidan (Winter Ghost Story), released in Japan on May 23, 2009.

Reference: Wikipedia