Here are the rules I usually follow:
-if she's tweeting in English, she is more likely to tweet you in English. When she is tweeting in Japanese, she is usually having conversations with her staff/dancers/Naoya etc.
-keep your messages short, basic, and simple English phrases. The short part is important because she will retweet you when she replies, and it's easier to do so if your original tweet is short.
-the past two times she has tweeted me, it has been to thank me for compliments. You're more likely to get a "thx" or a "-_^" if you say something like "I really liked (new release), it made me (emotional reaction)"
-questions or enquiries almost always get ignored. Either she can't answer them due to contracts/obligations to AVEX, or she just doesn't know. I figure all the times we asked her if we could visit her in LA this January went unanswered because her schedule was still so up in the air that she just didn't know
-the time of day can usually be a factor too. Thankfully I'm in California, and when she tweets somthing at 4 in the morning in English, I know that I am far more likely to get a reply because she is not getting a lot of English tweets at that time of day. Actually, the only times she has ever replied to me or retweeted me has been during the evening/night while she was in California.
Ayu has replied to me four times and retweeted my photos twice, which isn't as much as some of the people on here, but far more than most, so I hope my advice is good
