While watching episode 18 of Zettai Karen Children, at 10:49, some random characters seem to walk into the scene. And I seem to recall that the character that walks by is from some other series, all tough I'm not too sure which one.
So who is the guy in the middle of the picture that's getting hugged by this tiger?
Butler of the Sanzenin, Hayate, although underage, has had to work to support his unemployed parents. He moved from job to job since he was nine, but through this he has gained considerable and practical knowledge on how the world works. However, Hayate has terrible luck. Called a 'combat butler', Hayate is skilled with firearms and is physically invincible, even surviving after being hit by vehicles.