In the metal case that Mahara was carrying, there were a bunch of vials and capsules containing various substances. At first glance, it looks like a case belonging to some scientist or chemist, but in reality, these substances are various types of drugs.
Each of the substances has a different application and indication, but all serve as medications. So yes, this is a first aid kit. It's strange, after all, where are the needles, disinfectants, and bandages?
I also wondered about that the first time I saw this case. But even stranger was observing a deep 15-centimeter cut on the skin being completely cleaned with just 5 or 6 drops. Literally clean...
All the dirt and sand that was embedded in the cut was expelled after the drops started foaming and dripping. Then it was just a matter of applying some kind of coagulating powder, and the cut closed up as if days had passed. So yes, this case is definitely a first aid kit.