Alright so some people ask about Clear’s watch and why he has it/where he got it from. I’ll keep this short for people curious about it.
The watch is Clear’s coil that was previously his Grandpa’s, as shown in the photo Aoba finds of him in Re:Connect. It’s what he uses to call Aoba while in Overr Tower, and send him the map.
During Clear’s confrontation with his brothers, in the midst of striking his head to rid of his keylock, Clear’s watch is ripped off and discarded for the rest of the route. However…
The coil is returned to Clear in Re:Connect, but it’s broken as a result of Oval Tower’s fight. This also explains in Clear’s DRAMA CD why Clear says to Mizuki he doesn’t have a coil, because it’s broken, but the object is a momento from his Grandpa. Thus he’ll never get rid of it.