BOX

To more effectively assist the Conductor in driving, controlling various indicators, and handling some emergency situations, the BOX on Train No. CBCRR23, The Eternal, has undergone customized modifications experimentally.
For example, it invoked a more rational bionic dialogue database and computational logic in order to aid the Conductor—or at least that is what it believes—but when put to practical use, the unexpected still happened.
After the Conductor and Livia's information was logged into the database and analyzed for some time, The Eternal's BOX indeed accurately identified the Conductor, but it labeled Livia as "the person with the highest standing on this train." Despite numerous other people becoming permanent staff of the train afterward, BOX's beyond-deferential attitude toward Livia remained unchanged.
Even Livia herself is pretty baffled as to why this is so.

If you think about it, the fact that "there is more than one BOX in this world" is pretty scary. The existence of one BOX alone is already capable of causing chaos on the train. Should numerous BOXes converge on The Eternal and launch into BOX-style sarcasm at the Conductor in tandem... just the thought of it is enough to give you nightmares.
Out of curiosity for what exactly happened to BOX's mindset, Haruka once requested a robot repair technician who came by to inspect BOX's program logic, and the conclusion obtained was obviously "everything is fine." The technician even specially wrote a maintenance report to prove that not only were there no abnormalities in BOX's operation, but it fared much better than other same-model machines running for the same duration.
With this report, BOX became fairly smug about its state of health and started fulfilling its duty of supervising the Conductor's improvement with more resolve. There is no doubt it can work on The Eternal until the Conductor retires, judging by its excellent operating condition.
In other words, the days of living with BOX aren't going to end anytime soon.

It's said that new models of the Android Mechanic series are still continuously being developed, but most of them are prototypes that have yet to gain widespread popularity due to high price tags, lack of versatility in function, and so on. BOX is very keen on information like this, often looking unusually enthusiastic when receiving news on "new Android Mechanics," and it will even hop onto the small tables on both sides of the carriage to play the news on a loop.
The majority of the crew have already gotten used to this. Livia's comment is, "It's just like how pet hounds of the Empire's people get excited and wag their tail whenever they hear other pets nearby..."
BOX is oblivious about itself being analogized to dogs, but Livia is very worried about BOX getting too lonely and has been seriously considering whether or not to spend a fortune to bring in a new robot that can keep BOX company. Sadly, this idea has remained stagnated at the conceptualization stage, as getting a new robot truly costs a bomb.
"We'll have to depend on you to work hard and diligently supervise the Conductor's work, BOX! If our earnings are good, you just might get yourself a new friend!"
Nobody realized that while thinking that BOX "needs company from its kind," BOX's existence is already no longer just a pure android but more like... Hmm, more like what?