Saku gradually expands his friendship by participating in fieldwork at the Archaeology Club. Hayoma Kuzuno, who belongs to the singing club, turns up the heat on Saku and scouts him, while Sosuke also suggests that if he does not join the singing club, he should team up with him and aim for a major debut, but Saku refuses both talks. The reason why he stubbornly refuses to enjoy his youth is because of the presence of his sister Nozomi, who was sentenced to 3 months ~ half a year to live.