Yata's awesome wristwatch was given to him by Fushimi.
Name's the Same: Mikoto Suoh shares both his first and last name with an entirely unrelated girl from School Rumble. Technically speaking, the one from K typically has his last name romanized as "Suoh" while the one from School Rumble has hers romanized as "Suou", but it's still the same exact name; "ou" and "oh" are two different but equally valid ways to romanize a long "o" sound in Japanese.
Playing Against Type: Lucien Dodge, best known for his young teenager roles like Takumu, Keita, Waver, and Chili, voices Adolf K. Weismann; a 60+ year old villain (although to be fair, he doesn't look like he's 60 years old and is immortal). This could be a subversion, as the said Adolf K. Weismann is actually the Colorless King, the real villain of the show, controlling Weismann's body and the real Adolf K. Weismann have been body-swapped into a 17-year-old Japanese schoolboy.