I'm also going in July. Since I have no close contacts in Japan, I'm going to buy from a reseller shop.
I'm a bit paranoid buying tickets from websites such as YAJapan. I would like to buy them in person so that I know that I will get the tickets.
Considering Ayu isn't super popular at the moment, I'm sure it'll be a breeze to get tickets. I mean, if resellers were still selling CDL tickets last year, then arena tour tickets will be easy to obtain.
EDIT: Thanks Earth_Maiden! That's been on my mind, "How many tickets can I buy?" It's only my boyfriend and I going, so I'm feeling relieved that they're not brought individually!!!