Since meeting each other, Sonic and Tails have been inseparable, their friendship having grown to the point where they have a brotherly relationship. During the Gemerl incident, they are noted to have an "Unbreakable Bond", and they have even been referred to as the "fastest and greatest duo". Sonic himself sees Tails as a cute surrogate/adopted kid brother and looks over him accordingly. However, he also sees Tails as a dependable sidekick and treats him as his equal partner on their adventures, and has even called him "the coolest guy he knows." The fact that Tails can as well move at great speeds by rotating his twin-tails and can fly in the air has helped Sonic many a times when he has found himself in trouble. Additionally, Tails' skills as a mechanic, as well as his intellectual prowess has aided Sonic many times on his adventures. As such, Sonic places an immense amount of trust in Tails, who expands Sonic's range of activities and sometimes lights the way for him to go.