He must not grow if his otoshikami powers decrease =DDDD
But I can totally see last chapter... "Ok, I was joking... again, your reaction shows you still hold feelings for me. You should forget about me once and for all." Keima said with his signature poker face and Chihiro was perplexed, she wanted to cry, shout and kill him but she could only stand there. When she was nowhere to be seen, Keima looked at the bright blue sky with a tear in his face "For the first time... I wasn't. It's better that way." he said and went to school as usual