Temporary Storage in Shibuya or Shinjuku

My friend and I are going to a concert in Shibuya (CC Lemon Hall), but that night, we're supposed to take a night bus that leaves from Shinjuku at 24:20.

We were wondering if anyone had any ideas of where we can put our backpacks in the meantime (or if we can bring it into the venue, which we would rather not)...

There are coin lockers at Shinjuku and Shibuya Stations:
http://www.japan-guide.com/e/e2274.html

I don't know about the CC Lemon Hall, but at the Makuhari Messe, there are lockers for bags. I guess there should also be some at the CC Lemon Hall.

Depending on when the concert will end, you can also lock in your bags at the Shibuya station or most other larger stations. The lockers work till something between 10 and 11 PM, I think, depending on the size, they cost usually something between 300 and 500 Yen per day.
If those are large travelling bags, you should lock them in at the station, even if there are lockers at the CC Lemon Hall, they will be mostly for smaller bags.