The third anniversary event is over, and the lucky bags have all been sent out. There were two ways to get one of them, and one of those methods began with nothing more than a suspicious-looking link.
The game started the moment that link was opened.
It led to a post in the MoeYin community. At first glance, there was nothing unusual about it. But anyone paying close attention would have noticed that the comments were the real clue.
Those comments practically pointed the way forward.
Anyone who recognized the image in the post might also have realized it was just an avatar picture. The character details themselves were a distraction and had nothing to do with solving the puzzle. The important part was the image file.
The obvious idea was steganography. Once that possibility came to mind, the next step was simple: try decoding it, either with your own script or with an online tool.
As expected, the image revealed a Baidu enterprise drive address along with a mysterious code. Put the pieces together and you get a valid URL:
https://eyun.baidu.com/s/3kWo9zan
Opening it gives you an mp3 download. So naturally, you download it and listen.
Yes, it really is the theme song from Oreimo. If you listened to it once and closed the file, then that was the end of the road.
But did you actually listen carefully?
If you did, you would have noticed something was off. This was not an ordinary audio file.
The next move was to open it in professional audio software such as Adobe Audition and switch to the spectral frequency display.
That confirmed it: text had been hidden directly in the spectrogram.
Once again, the reward was a URL fragment and another code. Combine them and visit:
https://img.52ecy.cn/0072Vf1ply1g6s3uhuge0j30hs0hs3z8
That leads to an image host, where another picture appears. It is still Kirino, still striking the same cute pose.
But this image host was based on Sina’s image hosting, which meant the so-called mysterious code followed the same structure as a Sina image URL. That made it possible to decode it.
By working backward from the image address, you can recover the uploader’s UID. The algorithm used here is the same one discussed in “Who is Po Master?”
That process eventually gives:
https://weibo.com/u/6456124939
Once there, the first post stands out immediately.
There was one extra detail that mattered all the way through: look at the comments. That hint had been planted from the very beginning. Sometimes reading the comments really does help.
The final obstacle was the timestamp. How do you extract it, and why does it need to be 13 digits long? A 13-digit timestamp means millisecond precision, but the normal desktop page only shows time down to the minute, not even the second.
On the desktop version, that information does not appear directly. On the mobile version of the page, however, the source code contains the post’s creation time in created_at.
And that was the real end of the puzzle.
If someone still could not solve it, the problem was not that the plan was bad—just that the leap in logic needed to be a little bigger.
The whole event took more than a month to put together, and it finally wrapped up exactly as intended.