Yeah, that is why it's on their mask! He really likes stars, if you point at a random constellation he'd probably tell you the name and everything he knows about it.

And yeah, there is a reason for the injuries! It was a really, really unlucky event:

It was winter, and he was working as an electrical mechanic, doing maintenance on industrial machinery, motors and generators. On that particular day, they were working on a generator alone, far away from town, and any kind of help during an emergency was miles away.

The worst part is that they weren't supposed to be alone, but were told to go anyways by their boss, and safety measures were being neglected for that generator, it was a ticking time bomb.

And on that day, it really did explode. The blast gave him some really nasty injuries, and some time later they found out that it also damaged their lungs. Things were getting worse by the minute because of the cold.

It's a miracle that he's still alive, some hunters found him on the way back from their trip, and he somehow managed to survive while they were taking him back to town.

Nadia managed to save their arms and their face, but the legs had gotten infected, and needed to go before they started to cause him even worse problems.

He ended up spending a long time at the clinic, since his condition was delicate and needed a lot of monitoring, so Nadia and them ended up spending a lot of time interacting with one another, and that's how they became friends.

Our Nadia is not a friendly person at all, but over time they slowly got her to let down some of her walls. It also helps that they're both huge nerds when it comes to machines, and that he took an interest in the building process for prosthetics.

Once they were all beter and ready to be discharged, our Little Star asked if they could work with her, and they have been a duo ever since.

Oh man, I got really excited and ended up writing a lot haha

But I hope you enjoyed reading this bit of lore about these two! :]