So pretty much the part that everyone knows, Konami was trained by Kana/Asuka and she debuted on a Kana Pro show on February 25th 2015. Around this time Konami's show appearances generally revolved around the companies that Kana worked, mainly being WAVE and REINA.

Eventually Konami signed a contract with REINA at some point in 2015. Syuri at this time was pretty much one of the main people in charge of REINA at this time (to my knowledge) and had a large role in training there, so essentially Syuri is one of Konami's trainers.

In September 2015 Kana signed with the WWE and left Japan and I'll explain the significance of this. During this period, Konami started to struggle since she had moved from Hiroshima to Tokyo on her own to train and live with Kana and now she was essentially on her own.

"I didn't know what to do. I had no place to stay. I thought, 'What a cold city Tokyo is.' I was just trying to do my best." she recalls. (excerpt from https://www.tokyo-sports.co.jp/prores/stardom/1572105/)

This left her with a feeling of abandonment however Syuri was the one who helped her through this, which is reflected in the letter she wrote to Syuri during the Nippon Budokan Press Conference. (transcript by @elduderino112)

At this point Konami now treats Syuri as what she sees as the ideal wrestler and what she wants to become. Konami left REINA in mid-2016 to forge her own path and joined GPS Promotions before finally joining Stardom, meanwhile Syuri focused on MMA and signed with the UFC.

Flash-forward to 2020, Syuri and Konami are finally reunited in the wrestling ring when Syuri joins Stardom as a member of DDM, and they have a face to face encounter during the Cinderella tournament where Konami lost.

In a blog post, Konami lamented about how she was unable to show her growth in this match as the submission move that she dearly relied on, the Triangle Lancer, was easily defeated by Syuri.

Another flash-forward and Syuri has beaten Bea for the SWA World Title, and goes on to successfully defend it against Giulia, Momo Watanabe and AZM before challenging Konami to a match at the Nippon Budokan. Konami during this time period has betrayed TCS and joined Oedo Tai.

On Twitter, Konami mentions how the Syuri that she had long admired was almost non-existent now, and that she just felt like any other wrestler within DDM.

Konami stated she wanted to see the side of Syuri that she admired to return, not the one that acts as a second to her friends in DDM or plays and jokes around at press conferences which links back to the reason Konami betrayed TCS.

In the past, Konami has said that strength doesn't come from being friends with others in the ring as it holds you back which is why she joined Oedo Tai as it was full of betrayers, so she wouldn't get too attached to them as they could betray her at any time.

Essentially the match at Nippon Budokan is more than about the SWA World Championship, it's about Konami showing Syuri that the path that she found since their time apart was one that could truly allow her to surpass "the ideal wrestler".