For context how Japan’s Empress Cup is organized like this, 1st division teams automatically progress the first few stages and they’re entirely filled with 2/3rd division teams, youth teams, college and high school teams etc. I like this idea because it’s great opportunity for gaining experience for young players.
Last year Beleza played their own U18 team (called Menina). Honestly the first time I saw the matchup I felt a bit sad for Menina because INAC is having a legendary performance (undefeated and conceded only one goal at 9 matches) at the first half of the league. That makes all the more impressive that a youth team managed to defeat them.
Here is announcement tweet from official Beleza account https://twitter.com/tokyo_beleza/status/1474614096100466688