Answer the question at the end by quoting:

David Lee Marks (born August 22, 1948) is an American guitarist, singer and songwriter. He is best known as a member of the American rock band The Beach Boys, with whom he recorded four studio albums, and of whom he was a member from 1962 until 1963, again from 1997 until 1999, and lastly in 2012. Following his initial departure from the band, Marks fronted the Marksmen and performed and recorded as a session musician. A neighbor of the Wilson family - Brian, Dennis, and Carl Wilson - and a frequent participant at the Wilson family's Sunday night singalongs, Marks officially joined the Beach Boys in February 1962 as its rhythm guitarist.
In February 1963, Dennis Wilson was injured in a car accident and his replacement was Mark Groseclose, who went to high school with Carl Wilson. Marks and Groseclose became friends and Marks eventually took over Groseclose's garage band, the Jaguars, which he renamed the Marksmen. The band was initially a side project for the aspiring songwriter, who was growing tired of his songs being passed over for Beach Boys records by Murry Wilson.  After Marks left the Beach Boys, the Marksmen became his full-time focus, becoming one of the first acts to be signed to Herb Alpert's A&M Records in 1964. Murry Wilson reportedly threatened radio deejays in order to keep them from playing the Marksmen's records. Later, the group signed with (and released a single on) Warner Bros. Records, but in spite of packed concert venues up and down the state of California, lack of air play precluded any further releases. The 2009 release of Marks & the Marksmen Ultimate Collector's Edition 1963-1965 marks the first-time the entire Marksmen catalog was made available to the public.  In 1966, Marks played with Casey Kasem's Band Without a Name. He then worked with the late 1960s psychedelic pop band, The Moon, along with Matt Moore, Larry Brown, and David Jackson. The band signed a production deal with producer Mike Curb and released two under-promoted albums on the Imperial label. He also performed with Delaney and Bonnie, Colours (recording lead guitar on their second album), and Warren Zevon. By the time Marks was 21 years old, he had been signed to five label deals and had grown disillusioned with the Los Angeles music scene. In 1969, he relocated to Boston, where he studied jazz and classical guitar as a private student at the Berklee College of Music and the New England Conservatory of Music in 1970-71.

What made Marks leave the Beach Boys?

had grown disillusioned with the Los Angeles music scene. In 1969, he relocated to Boston, where he studied jazz and classical guitar as a private student

IN: Ai Kago (Jia Hu  Ya Yi , Kago Ai), born February 7, 1988 in Yamatotokada, Nara, Japan, is a Japanese singer, actress, author, and former Guinness World Record holder. Kago began her career at the age of 12 as a member of the idol group Morning Musume. In the same year, she became a founding member of Minimoni.

Throughout the second half of 2010, Kago became unhappy with the direction of her work. Around the same time, she began dating restaurant owner Haruhiko Ando, who acted as an in-between for her agency and herself. Since beginning a relationship with Ando, Kago cancelled several jobs at the last minute, causing her agency to suspend her activities. Despite this, she participated in a live performance and opened a separate blog without permission.  Kago parted ways with R&A Promotions in November 2010 despite her contract ending in March 2013. As a response, in 2011, Kazuyuki Ito, president of Mainstream (an associate of R&A Promotions), declared that the agency planned on suing for 100 million yen in damages for contract violations. During that time, Kago's career was also derailed by her personal life. In September 2011, Ando was arrested for alleged extortion and claiming to have connections with the yakuza. In the same month, Kago was rushed to a nearby hospital after agency officials found her on the floor of her apartment with cuts to her wrists. Her life was reported to be not in danger, though there were speculations that it was a planned suicide. Following the incident, she and Ando registered their marriage, and Kago became pregnant.  After spending 2012 out of the public eye with the birth of her daughter, Minami, Kago transferred to a new agency in 2013. Planning to revive her music career, she formed an idol group, which was later named Girls Beat!! The group would be crowd-sourced using lyrics, music, and costume ideas submitted by fans. Remi Kita and Ryona Himeno were recruited as the other two members after passing the auditions.  Girls Beat!! released their first single, "Sekai Seifuku" on July 22, 2014. Their activities were abruptly put on hold when an arrest warrant was put out for Ando in October on suspicions of loaning money at illegal interest rates. Kago later filed for divorce, planning to continue activities once the divorce was finalized. Although Kago was eventually successful in doing so, in August 2015, her contract with her agency expired, though she continued activities with Girls Beat!! in November. On February 29, 2016, she graduated from the group.

What struggles did she have?

OUT:
Kago was rushed to a nearby hospital after agency officials found her on the floor of her apartment with cuts to her wrists.