Artist's commentary
Reimu, I'll explain something important to you.
Your paste core was so severely damaged so the paste circulation no longer works.
Normally you will simply die but thanks to the paste circulation machine developed by Mister, it's alright.
This machine utilize a pump to force your pastes do circulating via the tubing connected to your body
As for the nutrition, yukkuri food are tossed into this inlet, made into something like pastes with a blender, and sent into you.
The staled pastes are pumped out here so there is no need to do poo-poo.
You will suffer from paste insufficiency and take it easy forever if the tubing is unplugged, so please take care of that.