On September 22–28, Hayakawa competed at the 2014 World Championships in Izmir, Turkey, where she qualified for the all-around finals after finishing in 16th position behind Elizaveta Nazarenkova of Uzbekistan.

In 2015, Hayakawa began the season competing at the 2015 Moscow Grand Prix, finishing 12th in the all-around and qualifying to three event finals.

Hayakawa won the all-around bronze at the 2015 Asian Championships behind Uzbek gymnast Elizaveta Nazarenkova.

In August, Hayakawa finished 16th in the all-around at the 2015 Sofia World Cup behind American Laura Zeng.

On September 9–13, Hayakawa (together with teammates Kaho Minagawa and Uzume Kawasaki) competed at the 2015 World Championships in Stuttgart, where Team Japan finished 6th.

In 2016, the Japanese gymnastics federation used the 2016 World Cup series to decide whether Hayakawa or Minagawa should compete at the 2016 Summer Olympics, as Japan could only send one individual.

[8] Hayakawa started her season competing at the Espoo World Cup, where she finished 10th in the all-around and qualified to the hoop, ball finals.

On June 3–5, Hayakawa finished 14th in the all-around at her last competition, the Guadalajara World Cup, with a total of 69.300 points.