Story-related and can't be missed. You'll unlock this trophy after the boss fight in the power plant and watch the cutscenes.
It's worth mentioning that everything in the Digital Shifts in the various areas are optional and are good for grinding and getting items but are otherwise skippable. The only thing worth mentioning that exists outside the shifts is Victory Uchida in Akihabara but otherwise the main focus is in Shibuya.
In round 1 you can't win the fight (spam guard and keep your Digimon healthy) and in round 2 you can't lose so you'll clear this chapter up in around 15 minutes or less.