I'm not a great people person - actually I'm a bit of an introvert. It's probably no surprise that I find it challenging to approach people who I don't know well for meetings that will always be tainted with language barrier awkwardness. But the more you do it, the easier it gets.
You may have experienced that some teachers will come to you, or at least be very approachable. Others will seem to avoid you until 2 minutes before the class, spit out a few misplaced English verbs while pointing to a Japanese lesson plan and consider the meeting done. (I'm mostly thinking of elementary school here.) Well, the more you chase these teachers down for a better meeting, the more they will realize you want a proper meeting about class and over the year, become a little more approachable.
Why meetings are good for your English class
Short term benefits
Having a good meeting, where you both come away fully understanding what is going to happen in the upcoming lesson means you will both be ready to contribute to the class.
It also means the lesson can be improved upon if either of you have any ideas during the meeting time. Often, planning will be left to one of you. Even if you aren't the one that planned the class, come with some ideas and if you think something can be tweaked a little to improve the educational experience for the students, speak up. Stay up to date on what you are teaching and have at least one game or activity ready to suggest.
After a meeting where everything is discussed, the HRT will be more confident about the class. The unknown is scary, so explain what is going to happen and what the HRTs role will be (if they aren't the leading type). Additionally, a meeting is a good time to practice any "unscripted" conversations (that somehow relate to what you're teaching, obviously) you plan to have with the HRT.
If you can do this, it'll put the HRT more at ease and your students and class will reflect that.
One long term benefit of having meetings before every class are that you get to know your teachers. This can really help with the grumpy ones. Once they get comfortable with you, their dislike for English can fade a little.
It also good simply to be in good habits. If you start avoiding meetings then that becomes a habit too. Teachers will expect that behavior of you and probably just let it go. The result - the students lose.
They end up sitting through poorly planned lessons and start to see their teacher look less and less enthused about upcoming English classes. They will eventually start to reflect this attitude and classes become harder for you to teach. Do it right from the start.