The Japanese swim star and Rio 2016 Olympian entered for women's 50 free in Tokyo - her first since cancer diagnosis 19 months ago.
The 20-year-old Japanese star has entered the women's 50-meter freestyle of a two-day local competition, according to the start list issued by the Tokyo Swimming Association.
Ikee's last competitive appearance dates back to a low-key Tokyo meet in January 2019, a month before her cancer diagnosis.
The Rio 2016 Olympian and record setter posted a video of herself working out ahead of the weekend.
Ikee broke the Japanese national record in the 50 free with a time of 24.21 seconds, a mark she cut in April 2018 before going on to dominate the Asian Games that year. She stormed to six titles in Jakarta and was named the Games MVP.
Tipped as a medal favourite for hosts Japan in the pool at the Olympics in Tokyo, Ikee's cancer diagnosis ended her hopes of competing at the Games in 2020.
She was released from hospital in December 2019 following treatment, and this March took her first dip since falling ill, before featuring in the One Year to Go ceremony held at the Olympic Stadium last month.
The 12-month delay to the hosting of the Olympics due to the coronavirus pandemic had fans hopeful that she might be able to return in time to take part in her home Games in 2021.
The Tokyo native has only spoken about eyeing an Olympic comeback for Paris 2024.
Ikee has said she is targeting the national collegiate championships in October. The qualifying standard for that event in the women's 50 free is a 26.86.