The team competition for the Matsugorou Cup begins and among the participants is Mai Tanuma, who is Setsu's childhood friend, Yui's friend on social media, younger sister of the prodigy Souichi Tanuma, and daughter of the accomplished shamisen performer Kamiki Ryuugen. Mai gets upset when she finds out that Setsu is competing, but is unable to participate in the individual competition. Setsu walks out of the concert venue intending to skip the opening ceremony and meets Souichi, while at the venue Mai meets Yui in person for the first time...