The fighters in question are former WBA female Minimumweight champion Etsuko Tada (13-2-2, 3) and former WBC female Flyweight champion Shindo Go (14-3, 9) who both lost recent bouts in Mexico.
For Tada her loss was a very close, and relatively controversial, defeat at the hands of Anabel Ortiz, who has now beaten Tada twice by split decision. That loss saw Tada attempting to reclaim her world title from Ortiz though the judges didn't seem to be impressed by her. As for Go she lost her WBC title to Arely Mucino courtesy of a slow start that she never quite recovered from.
The show is said to be a show that will help to reinvigorate female boxing in Japan and the hope is that if both fighters win in April they will be moved towards world title bouts later in the year.