I have to agree; one of my favorite characters in the show is Hatori. A fun fact that doesn't get explained in the anime, but (in case it wasn't obvious) Hatori is actually the zodiac's dragon. In Japan, seahorses are considered a type of "water dragon", and Shigure explains in the manga that the reason for the "transformation shifting" is because the original Soma bloodline has been too heavily diluted from marriages "outside" the family clan. In other words, at one point in time, the Soma's dragon DID actually transform into a full-fledged dragon, but now that the bloodline is diluted, the current Soma dragon - Hatori - is only able to transform into a seahorse. (Hence why he blatantly threatens to ruin Shigure's professional reputation when Shigure asks Tohru if she knew what zodiac Hatori was; it's a point of embarrassment for Hatori.) Him being the dragon is why he's the family doctor, as well. Dragon's are believed to have healing capabilities. It's also why Hatori is the only member of the family that can erase someone's memories (and even rewrite someone's memories, as he mentions this episode). Overall, he's just a very powerful character but is also very humble and respectable and reserved, and I really appreciate that about him.