I just made my first Chuurenpoutou ever, but this one was in 3er though at the SEGA MJ site.
Started with two

and two

- wound up having to wait for the last

for it, but my lesser valuable waits were

and

- got it on a ron, from the same guy who threw out a

earlier in the hand.
That said, is Chuurenpoutou that tough even in 3er? - it is definitely up there in difficulty in regular 4er for sure, much less the Junsei version of it...