How do I deal with People that play overly defensive?

First of all, I wanted to say that I really, really love how fast-paced this game is and how fluid the tagging and combos work. I understand and see the fun in all the mechanics, like countering and swapping mid-combo. If someone does it better than me or defeats me, I’m not even angry; I just say to myself, 'Damn, they're better, but that was a good game, I had fun.'

However, there's one type of player I never have fun with, and I don't know if it's in the design or my own fault for not knowing how to counter it. My problem is: overly defensive players that back up all the way to their half of the screen and start blocking like little pussies, only attacking me when they see a window or a mistake of mine.

​Honestly, I don't really know how to counter that. How do I get through someone backing up and blocking? Did I miss something in the tutorial? Am I just an idiot? What am I missing?

​Nonetheless, even if I’m just stupid, this has to be the most unfun way to play this game for both parties. Bonus points if we make it into overtime and they stall until the timer or health bar kills me.

​(This is my first fighting game and I’m only here for the IP, so please consider that before answering.)