Help identifying hose spraying air and fuel?

Pretty sure this is correct. Diagram here: https://www.ttguide.net/components-826.html

 

I'm kinda inclined to agree with TenBeers, it can't really be a high pressure line if the critter was able to chew through it

 

There is no return from Hight to Low systems. Pressure regulates via spill control valve. page 101

 

Yea return system isn't the right word, but it bleeds pressure to the low pressure system.

High pressure bumps definitely need somewhere for pressure to go. It's quite clever how toyota laid out the D4S.

 

Here is a better view of hpfp and the lines from a different toyota model with d4s.
Orange marking is low pressure line

 

Looks like it is a low pressure fuel line. The connector where the line is chewed is going on the metal tube end. Perhaps it you can fixed by cutting the tube and put it back on, but the pressure still around 70 psi when the key is on on low pressure line.

 

Oh man, I'd fix that in about 2 minutes as long as there's enough slack in the line to cut away the damaged piece and reattach to the metal line. Slap a hose clamp on it for good measure.