2021 In 2021, Iwanaga and Nakanishi reached their first Super 500 final at the
Hylo Open in November. They were defeated by their compatriots,
Chisato Hoshi and
Aoi Matsuda, securing runner-up position. Their 2023 season also included reaching the quarterfinals in five other tournaments: the
India Open, the
Thailand Open, the
Singapore Open, the
Korea Open, and the
Australia Open. They finished the year by returning to a world ranking of No. 15, after their ranking had dropped to No. 26 earlier in the year.
2024 In 2024, Iwanaga and Nakanishi reached the quarterfinals of the
Malaysia Open in January by defeating third seeds,
Kim So-yeong and
Kong Hee-yong, marking their first quarterfinal appearance at a Super 1000 tournament. They won their first Super 750 title at the
Denmark Open in October. This win was their fifth consecutive tournament final victory in 2024, following titles at the
Spain Masters, In the final, they beat the
Paris 2024 Olympic silver medalists and then-world No. 1 pair
Liu Shengshu and
Tan Ning (21–18, 21–14). This victory solidified their position as the second-ranked pair in the BWF World Tour Finals rankings and was their second win over Liu and Tan in three encounters. Despite these injuries, Iwanaga and Nakanishi reached the final of the
Singapore Open (Super 750) in June, finishing as runners-up to
Kim Hye-jeong and
Kong Hee-yong of South Korea. Iwanaga and Nakanishi reached a new career-high ranking of World No. 4 on 11 March. Additionally, Iwanaga was also part of the Japanese teams that won bronze medals at the
Asia Mixed Team Championships in February and the
Sudirman Cup in April. == Personal life ==