In January 2019, Mandy was chosen as a representative for the promotion of the American movie Aquaman in Japan. On February 14, he attended the PRINCE OF LEGEND PREMIUM LIVE SHOW, a fan-meeting with the whole Prince of Legend cast, at Yokohama Arena. On March 18, Mandy was invited to throw another first pitch at the opening ceremony of the Giants vs Mariners baseball game at Tokyo Dome. However, he wasn’t able to exceed his previous record. On June 4, it was announced that Hello Mandy won the No. 1 prize in the collaboration category of the Sanrio Character Award, an award based on an annual popularity voting. On July 17, Generations from Exile Tribe released the single “Brand New Story”. It included “Control Myself” as a B-side track, being the group’s first original English song and also the first one to feature Mandy as a rapper. On September 9, it was announced that Mandy would be part of the cast for the live-action series of the manga Motokare Mania (モトカレマニア; Ex-Boyfriend Mania). This would be the first time that he will appear in a prime time drama.

On June 5, 2018, he threw the first pitch at the opening ceremony of the Giants vs Rakuten baseball game, held at Tokyo Dome. His appearance garnered great public attention since the speed of his pitch reached 133 km/h, the fastest thrown by an entertainer at that time. His record was broken by Golden Bomber’s Kenji Darvish later on (135 km/h) and both developed a comedic rivalry. On August 31, Sanrio announced they would produce a new character, Hello Mandy, based on Mandy Sekiguchi. The character is designed with an “M” lavaliere on a necklace and one of Mandy’s most familiar hairstyles.

In August 2017, Mandy produced the 24karats×KANGOL collaboration collection of designer hats. 24karats is a fashion brand developed by LDH while KANGOL was founded in 1938 as a British traditional beret brand which established itself as a symbol of the art scene. Additionally, he made his acting debut in LDH’s movie universe HiGH & LOW in the same year.

In 15 April 2016, he became a member of the hip-hop unit Honest Boyz. He took on the position of MC in the group, calling himself simply Mandy (stylized as MANDY). This marked the first time he would use his vocals in a group.

Mandy advanced into acting for the first time in April 2014, when he was selected as a cast member of Fuji TV’s late night program Wow. On April 27, 2014, Mandy passed the EXILE PERFORMER BATTLE AUDITION FINAL in NIPPON BUDOUKAN and became a member of Exile. In May of the same year, he made his stage debut in the stage play DANCE EARTH PROJECT “Changes” while also joining the coed-group Dance Earth Party for one year.

In April 2012, he became an official member of Generations and debuted in November of the same year.

In April 2011, Mandy participated in the Exile Professional Gym (EXPG) audition produced by Hiro, and he was selected as a member of Generations from Exile Tribe.

Mandy Sekiguchi (関口 メンディー; Sekiguchi Mendi, born January 25, 1991, in New Jersey, United States) is an American-Japanese dancer, rapper, actor and a member of J-Pop groups Generations from Exile Tribe, Exile and Honest Boyz.

Mandy Sekiguchi was born on January 25, 1991, in New Jersey, United States and grew up in Shinagawa, Tokyo. Even though he was born outside of Japan, he was raised monolingual in Japanese and only started to study English later on in his career. He started playing baseball at the age of 6 and practiced it till his third year in high school.