[4] He was only 10 years old when he entered show business, and it is said that he had a rebellious period due to the frustration of not being able to CD debut quickly.
[5] At the Johnny's, which had a strict hierarchical relationship, he surprised everyone by calling his seniors without an honorific title.
[6] When he met Shingo Katori of SMAP, the most successful group in Johnny's at the time, he scared everyone by saying, "Who are you?.
[7] After joining several groups as a trainee (Johnny's Jr.),[8] he was selected as a member of Kis-My-Ft2 in 2005, and he made his CD debut with Everybody Go on August 10, 2011, seven years after their formation.
[10] On December 13, 2013, Busaiku was formed from Kis-My-Ft2 with Kento Senga, Toshiya Miyata and Wataru Yokoo produced by Masahiro Nakai who was a member of SMAP.
[16] On January 18, 2025, Nikaido held a return press conference via live streaming on Kis-My-Ft2's YouTube page.