Moving from the countryside, Takada is a new arrival in class. Once he hears that Nishimura is referred to as a "Grim Reaper", he immediately takes an interest in her and moves in to become her friend. He thinks everything about her is awesome, and seems completely oblivious to everyone else's bullying attempts.
His almost relentless optimism might be why the show is named as it is, but he isn't entirely clueless. He's able to put two and two together about how he potentially might have hurt Nishimura with his comments. (Which usually turns out to be a misunderstanding on his end.)
