See my original sketch from 2020 here: https://www.weasyl.com/~guineapigdan/submissions/2131446/cat-tummy-inspection-2020-sketch
Another sketch that I've colored traditionally. Gel pens and copic markers were used for the characters, while the couch was done with colored pencils. Basho had noticed Peter's weight gain and decided to press his head against his feline friend's belly to see how much softer he's gotten. Peter hadn't eaten though so as Basho relaxed his head against his pillow-like belly, it spoke up and demanded to be fed. If someone wants to lay against Peter's belly, it's going to charge admission and ask for lunch.
Again, thanks to ChiefScarneck for providing the Japanese translation.