Features "Morning Musume.' 21 Concert Teenage Solution: Sato Masaki Graduation Special" held at Nippon Budokan on December 13, 2021. Masaki Sato, who joined Morning Musume. 10th term member after passing the "Genki-Jirushi Audition" in September 2011 and has been active for about 10 years and 3 months since then, graduated from the group after this concert. This was the group's first solo concert in about two years.