This comic is by Iwano. You can buy it here: http://alice-books.com/item/show/1201-20

Iwano's twitter account is here: https://twitter.com/iwano_29

I tried my best at scanning these pages, not really that familiar with scanning comic books and such. Hopefully this will suffice.
This is only in Japanese, and I'm not familiar with translating. Google translation (the phone app) gives broken English as always lol.

Hopefully, you enjoy this fun belly growth comic as much as I did!

This isn't really my type of thing. However, I did have a good laugh at the pg. 13 spread over two pages.

Base +8

I've shown it to a few friends, they found it cute and funny at the same time. I think it's meant to be both lol.

Base +5

Hey this is great, thanks a lot for uploading!
Not really into "character becomes a big circle" but iwano manages to make it hot!

I hope someone uploads Power tiger too.

Base +1, Shouta Hamasaki +6, black‖dream +6, copperheart +8

@Gyuudon Diamaou

Me too, I'm not into the huge inflation thing, just the small weight gain was pretty nice to see haha. And I love dragons with bellies so there's that!

Base +5, MacXIII +6