People may knock the Okawari OP for not being as light hearted as the Season 1 OP animation, but if you think about it a bit deeper it's actually quite funny.
-Haruka dramatically makes a phone call in the middle of nowhere
-Kana dramatically dives into the ocean and goes for a swim underwater, seemingly in search of something
-Chiaki dramatically opens up a roof tile (lol)
-Fujioka the person dramatically flies down from the sky
-Fujioka the bear dramatically flies up into the air after a running start and pwns the blimp
It's not laugh out loud funny, but it's funny in the sense you know these things don't actually happen, so it's like a parody of itself. I do like the song by itself as well.
As for the ED though, I think they didn't put much effort there with just Kana just walking on the railroad tracks. The OP animation is much more interesting to watch. But the song itself is okay.