||I'd just like to say that our info is reliable on this, and that the info we've gotten comes from sources we can't reveal. I hope our reputation can suffice here.
We at H!O talked a lot about whether to reveal what we know. Surely everything will be revealed, in time, from larger news outlets. You can choose to believe this or not, but:
Maki planned/hoped to quit this summer and have her graduation on her birthday concert, but UFA insisted she wait until the final concert last month. Her decision to leave has nothing to do with the news about her brother Yuki that came out around that time.
She has zero plans right now to return to show business with UpFront, and has been looking for new companies to work with since last summer.
The main reason is that Maki is overworked and stressed out. The schedule that UpFront had for her was way more than she could handle. She's been having health problems lately due to this, as has been documented in some of her blog posts and UpFront announcements. Also, she and Up-Front had different ideas for the direction of her career.
The last we heard, she had no official contract with any other talent agency or record label (although actually, very recent rumors persist that she has signed somewhere). Despite what the press releases say, she is NOT with Up-Front anymore.
Her plan was NOT to quit showbiz, but just to leave UpFront Agency. However, as of right now, her status is unsigned, with anyone. She *currently* has no plans to return to UpFront, but anything is possible.