I don't know which is more impressive, Jun being willing to strike from behind or Gorou being able to dodge it anyway.
Jun is completely outmatched lol. Tomo's gonna have to step in and put an end to this nonsense.
Prediction: Akemi will eventually threaten her husband if he doesn't "lose" on purpose and let Jun date Tomo. We all know who is in charge in that family. (BTW Jun, you're looking at your future.)
He could have gone on other route like using your brain as a way to defeat Tomo's father. The "You need to defeat me to date tomorrow" thing has too many loopholes.