First cut: Kou Yoshinari.

I believe Kou did also the explosion/fireworks at 0:18

kyouray said:
I believe Kou did also the explosion/fireworks at 0:18

Someone pointed out to me that the explosion could have been re-used from this CM: post #128000 with some modification in the timing, but i'm not sure, the drawing seems a bit different and the composite of the old CM make it hard to see some shapes in the explosion.

Nice catch, shapes are very similar and there are some similarities in some patterns.
I'd have thought it's Kou since he can draw smokes like this but that person may be right, it feels re-used as if the animator redrew some parts of it and modified with composite.