Following the encounter, Nagaoka, who did not know much about pair skating at the time, decided to attend the 2019 Japan Eastern Sectional Championships to watch then newly formed team, Riku Miura/Ryuichi Kihara, compete.

The experience made Nagaoka want try competing in the pairs discipline, however, at the time it was difficult to find a Japanese male skater that was interested in teaming up with her.

[6][7] That same year, remaining in Sapporo, Nagaoka moved her training to Fuji Women's University, where Naomi Takagi became her new coach.

Marcotte ended up introducing Nagaoka to his other student, Sumitada Moriguchi, whose previous pair partnership had recently dissolved.

It was also announced that Nagaoka/Moriguchi would primarily train at the Kinoshita Academy, where they would work with coaches, Mie Hamada, Cathy Reed, Satsuki Muramoto, and Hiroaki Sato, while also making frequent trips to Oakville, Ontario, Canada to work with pair skating coaches, Bruno Marcotte and Brian Shales, at the Oakville Skating Club.

[14] They were named to the 2024 World team on the condition that they could obtain their technical minimums at the 2024 Bavarian Open or the 2024 International Challenge Cup.

[1] Going on to compete on the 2024–25 Grand Prix series, Nagaoka/Moriguchi scored personal bests in all competition segments at the 2024 NHK Trophy and finish in seventh place overall.